problem with a 73 marquis stalling
hey guys! i have a 1973 mercury marquis 460 sedan. now the when I take the car for a ride after about 5 minutes the car will have a complete loss of power the gas pedal stop responding and if I keep the pedal down the car starts jerking and doing backfires then stalls and wont start back up. if I wait 5 minute it will start again but then does the same thing 5 minutes later. the first thing I did was replace the fuel tank, fuel sending unit, fuel lines, filter, fuel pump and put a carb kit in it. that did not fix the problem so I installed a new distributor, ignition coil, spark plugs ignition wire, still did not fix the problem. put a new air filter also tried running the car without the air cleaner assembly did not fix anything, I also checked the EGR, alternator and battery and there all fine. so im wondering if you guys had any idea where I could look next? thanks you for your time!
I wonder what the timing chain looks like. Is the timing stable when you put a timing light on it or does it vary a lot?
I did not check the timing on the car since it only has 30k original miles but this is probably what I am gonna do next
Sure sounds like the typical Ford ignition module failure. Have you replaced that yet?
no, i searched online and check my shop manuals and cant find anything about an ignition module on my car. could it simply be that i dont have one. or maybe mercury called it something else
If it has one it will look like the picture. If it doesn’t have this then recheck your distributor for a bad breaker plate, make sure the little ground braided wire is in good shape and change out the condenser, rebuilt units just aren’t what they use to be. Also check for distributor shaft wobble.
ok, so I went to my local shop and bought a new condenser also ordered a timing light since I was there. I installed the new condenser, the shaft dosent wobble and the braided wire looks good. the breaker plates isn't loose and if I give it enough force I am able to rotate it so I am assuming that's its good. unfortunately it is snowing outside so I am not gonna take the car out to test if the condenser made a difference but tomorrow is supposed to be nice outside so I will go for a run first thing in the morning! also I gave the engine bay a thorough search and I couldn't find an ignition module should I also go and check under the dash?
Assuming your Mercury has the original ignition system you have a conventional ignition system. Points and condenser. Did you replace the points? Is the thermostat controlled air cleaner working? In cool damp weather a phenomenon known as carburetor icing would occur if the air going to the carburetor wasn't preheated. If ice forms on the carburetor it will stall the engine. Then a few minutes later, when the ice melts, the engine will start and run fine again until the carburetor ices up again. To confirm this when the engine stalls get out , pop the hood, and remove the top of the air cleaner assembly. Look for white frost on the carburetor and inside of the carburetor. If that's what you're seeing, the thermostat controlled air cleaner needs repair. Hope that helps! Jim
No need to look for the module as it has standard ignition.
so, I went for a ride after the few things I changed and the problem still occurs and for the carburetor icing i doubt it since the car also does this in the summer times but thanks for the suggestion i really appreciate any input on this
also i was thinking last night when i installed the kit carb in the car it didn't come with a float and the one i had seemed fine so i decided to reuse it. Could it be that there is a tiny hole in the float that makes it so that it slowly fills with gas and then stay open and drowns the engine then after the car stalled it slowly empties itself then goes back to normal it probably sound like a long shot but im kinda grasping for ideas right now...
I’m wondering if the resistor wire is trying to go open once it get warmed up, it’s the positive wire to the coil. Or a problem with the ignition switch.
If it was the float you would see black smoke out the tailpipe and it would not start back up without holding the gas pedal all the way open to clear the flooded engine.
ok, also when i went to the shop i picked up a thermostat since its pretty easy to change and cheap i might as well replace it and cross it of the list of possibilities.
As I recall old Fords had nylon timing gear teeth which break off. After I replaced the gears and chain on my Cougar the engine ran like a top.
i also heard of nylon gears on these old car. i ordered a timing light and im gonna receive it Saturday if the timing is off by more than a couple of degrees im putting a new timing chain and gears in there!
If you do make sure you get the timing set that has the key way lined up with TDC tooth on the gear set. They use to make three sets for this engine, retarded, stock and interceptor, and double roller chain.
hmm was not aware about that. thank you will make sure to get a set of stock ones.
A lot of parts people are also not aware of it. Hope you don’t have to tear it down but now you’re ready.
quick update i changed the distributor advance unit and the thermostat, thermostat reader/sender. i also change most of the vacuum lines. the car still stalls but if i try to restart it right away it will start if i dont touch the gas pedal but if i try to go forward it will stall again. if i give it any gas what so ever while trying to start it it wont start im not sure if it was that way before and i notice this phenomenon or if its new
Accelerator pump not working?
That or the needle is sticking. Was the carb kit upgraded for ethanol fuel? If not that maybe your whole problem.
i doubt it since i grabed your standard off the shelf carb kit and i might be mistaken but wasn't ethanol standardised in 1972? meaning my 73 was meant to run on ethanol. for the accelerator pump i didn't even touched it yet since the car will jerk even if i feather the gas but im gonna go take a look at it
also! i doubt the needle is sticking since the needle is in a triangle form in a cylinder so it dosent really have any surface to stick to.
Sounds like it's getting too much fuel, or not enough air. Is the automatic choke opening up? Many Ford Products of that era had a choke heat tube that went from the choke housing on the carburetor down to one of the exhaust manifolds. It's purpose was to pull hot exhaust gasses past the choke coil to open the choke plate as the engine warms up. If the tube is clogged, disconnected, or missing the choke may not be working properly. Hope that helps! Jim
Your thinking of unleaded fuel back in the early 70's not ethanol gasoline mix as we have today . If I remember right ethanol fuel was introduced in 2002 as E10 unleaded.
ok i have done some research and yes your right. i will look in what they call 'ethanol ready' carb kit thank you for the info. for the choke heat tube i haven't look into but first thing in the morning im making sure its working properly thank you Jim!
quick update I looked at the choke heat tube and it not clogged I also tried the car with different choke ajustement and it didn't help. I went to get my timing light this morning and the place I ordered it from told me they had trouble with there suppliers so it gonna take me at least another week to get it.
oh and the accelerator pump works!
and I forgot to mention I did a compression test on my engine and its in great shape! the lowest reading I got was 124 and my highest 134 so I have that going for me.
Thanks for letting us know! The more we cross off the troubleshooting list, the closer we get to having it fixed! Jim
Getting the timing dialed in is the first step. Make sure the choke is working properly, closed when cold and open when warmed up.
yep will make sure everything is well adjusted before the timing light arrives. I also ordered some lead substitute for my gas might help the car.
update! I went lo my local airport and bought 15 gallons of 100ll which is ethanol free leaded fuel. im gonna drain my fuel tank replace my fuel filter and fill the car up with this gas see if it makes a difference.
after i have checked the timing.
I'll be curious about how that goes! 1973 Ford Products were designed to run on the "new" low or no lead gasolines that were making their way onto the market at the time. Here's a photo from the 1973 Ford Owner's Manual that came with the 73 LTD our family had when I was a kid. Since you don't have a catalytic converter using leaded gas won't hurt anything and the higher octane may help. I was also just thinking about your gas line routing. Could you be experiencing vapor lock or a problem with the EVAP system? Try this, drive the car with the gas cap off and see if it behaves the same way! If not, you've got something going on with the EVAP system. Many years ago a friend had a 74 Impala that wouldn't run right if the gas cap was on tightly, as it was supposed to be. Loosening or removing the gas cap would solve the problem. What was going on was the vent valve for the EVAP system was stuck closed and a vacuum was being created in the gas tank. With the gas tank in a vacuum the fuel pump couldn't pump gasoline to the carburetor. As for the vapor lock theory, make sure the fuel lines are routed correctly and not too close to the hot exhaust manifold or exhaust system. Hope that helps! Jim
wow! ok the evap system is not something im too familiar with and iv hear of the term vapor lock before but im not actually sure what it means so im gonna go ahead and inform myself. Thanks a lot this is something I haven't look into and im glad you sent me into a new direction as I was running in circle at the moment. also thank for the info for the gas I looked around on the internet as to when ford started making car that where designed to use unleaded fuel but couldn't find any definitive answer. I cant wait to get up tomorrow morning and start working on the car! haha!
ok so iv read a bit on the subject and I understand it better. what I will do tomorrow is a have some heat shield which is a pray I use when welding to protect wires, plastic etc.. im gonna spray some on my fuel lines then go for a ride to see if it fixes my problem and honestly I have a gut feeling that it will!
Vapor lock is bad but you don't get it after running the engine for a few minutes. It occurs when there is a lot of heat under the hood. Good Luck!
You're welcome. Glad to help! Vapor lock is when the liquid gasoline boils in the fuel line into a vapor before it reaches the carburetor. With the lack of liquid gasoline getting to the carburetor the engine stalls. Hope that helps! Jim
finally got my timing light! tested my car 5 minutes ago and the timing is great! its advanced by 1 degree and is very stable. I would like to get your inputs because I feel like its good but my father told me that its bad, a car should never be at around TDC so... please let me know what you think
A one degree variation is fine. Did you check it with the engine fully warmed up, parking brake set, transmission in drive, vacuum advance hose at the distributor disconnected and plugged, high beam headlights on, and the air conditioning off? I remember doing this with my Dad years ago on our LTD. For some reason having the high beam headlights on is important. Fords required that back in those days but GM didn't. Hope that helps! Jim
Also, a worn timing chain is indicated by the ignition timing being retarded (late) not advanced. Hope that helps! Jim
Ignition timing should be 6° BTDC. Hope that helps! Jim
Yep 6 degrees with a plus or minus 2 degrees For fuel concerns
ok so I will check my timing again whit these different thing activated on my car then adjust it to 6°. thank you for the feedback! I didn't have the time to mess whit the car too much today so il try to look for vapor lock tomorrow.
1 degree of advance is not good. Like the others say I would use at least 6 degrees but you might want to try 10 degrees. It may run better and have better throttle response. The possible negatives are excessive ping.
Yes, BTDC is the abbreviation for Before Top Dead Center. Hope that helps! Jim
Hmmmmm, with the ignition timing advanced that much, is the distributor clamped down securely? Is the vacuum advance working? Are the centrifugal advance weights on the distributor free? On a 30,000 mile engine the ignition timing shouldn't be that far off. Check the items I mentioned. Something doesn't seem right to me. Hope that helps! Jim
will do! also I might try to put 10° on it I usually run premium gas so pinging shouldn't be an issue
centrifugal advance wei…. what?!?! iv never heard of dose! let me google that....
but hem kidding aside the distributor is securely clamped down and iv put a brand distributor timing advance with new hose on it last week so I am assuming its working well
ohhh ok the centrifugal advance weights are the things under the breaker plate. I was wondering what those things where! welp now I know.
i bought a brand new distributor 2 weeks ago and swaped everything in it into my old distributor the only thing i did not use is the shaft and the centrifugal advance weights (because i didn't know what they where) il go ahead and swap thoses as well tomorrow
Different weights and springs will change the spark advance curve. The total advance should be 32 to 35 degrees. A hot rod trick is to use a lot of initial advance and less centrifugal. You may want to experiment to see what works best. You can buy kits with different springs and weights to alter the advance curve. For now stick close to the stock specs.
This might help. https://www.badasscars.com/index.cfm/page/ptype=product/product_id=76/category_id=64/m ode=prod/prd76.htm
Or this. https://help.summitracing.com/app/answers/detail/a_id/5156/~/what-is-total-timing%3F
nice thanks and yea im not looking for performance so il try to stay as close as possible to stock
Hopefully your timing light is the type that allows you to dial in the spark advance.
i might be mistaking but on these older models cant you just turn the distributor to change the timing?
That's correct. You turn the distributor one way to advance the ignition timing and the other way to retard the ignition timing. Removing and replacing the distributor assembly will definitely throw the ignition timing off. That explains why it was so far off. Thanks for that info. As the engine RPMs increase so does the speed of the distributor. The centrifugal force causes the weights to move outward and increase the ignition timing. Hence the name. Hope that helps! Jim
ok, thanks for the input!
ok so this morning I went ahead and played with my timing. once fully warmed up the timing is at 1° I tried unplugging the vacuum advance turning on the ac, radio, high beams, dom light parking break... everything I could think of and the timing didn't change at all. so turned the distributor counterclockwise to increase the timing. I advanced it while the car was running and if I advanced it any more than 5° total the car would start jerking ans threatening to stall. so set it a 5° give the car some gas and it start to ping like crazy so turn it off try to restart it again and it would not. when I tried the engine would only turned once every second or so. decreased the timing to 3° the car still wont start. so down to 2° the car start but if I give it gas it pings! so i put it back to where it was at 1° and it stopped pinging when I give it gas. im also pretty sure I was advancing the timing because on the wheel there is an arrow with BTC on top of it which I think means before top center also if I turn it the other way around there an arrow with ATC above it so im pretty sure that I was doing this right.
What you stated concern me some, it is not unheard of for the vibration dampers degree wheel to slip cause it is mounted in rubber and the age of the vehicle would make this possible. Remove the distributor cap and rotate the engine to TDC on number one, the distributor rotor should be pointed directly at the number one position on the distributor cap. For it too bad at 5 degrees is not right as specs is 6 degrees. Some other things that I have questions about was what is the manifold vacuum at idle and if you have checked for restrictions in the exhaust system.
just tuned the engine to tdc and rotor is on the number one piston. actually all this is with me thinking that my number 1 cylinder is the one closest to me on the left of the engine (im gonna go make sure this is correct) I haven' checked the exhaust system BUT when I went under the car I saw some cut off supports on the right side of the car ( the exhaust passes on the left side) so the car either used to have dual exhaust or someone routed the exhaust on the other side when they changed it. and for the manifold vacuum how do I check this? do I simply unplug the vacuum at the manifold and check if the lines... sucks.
ok the piston I taught was number 1 is indeed number one. just wanted to make sure
also went for I ride with the car this morning. I coated the fuel line with some heat shield, removed the fuel cap and put 5 gallons of 100ll gas in the car and it will still stall
Looking at the timing mark gauge you want the timing mark to be to the left of the TDC mark as viewed from the front of the engine. It's also very important that you have your timing light hooked on to the number one cylinder spark plug wires. See the picture for your cylinder positions. Number one is on the front passenger's side of the engine. Hope that helps! Jim
A simple vacuum gauge is all you need and just hook it up to the intake manifold tee towards the back of the engine to get the reading. With the symptoms you are describing it sounds like something is either restricting the exhaust flow gradually to the point where it can't breathe or is restricting fuel flow as you drive it like a fuel line collapsing as it runs, then when it shuts down eithe the pressure bleeds off or the lines re-expands and it starts all over again. But I'm still bugged by the pinging at 5 degrees advanced, the last time I ran into an engine that did that the vacuum advance unit had broke the internal spring and was making the distributor go fully advance the instant the diaphragm got venturi vacuum from the carb. Times like this make a guy wish he could be there to see first hand.
yep had the right cylinder hooked up and form the front of the engines I put my timing 5 degrees to the RIGHT of TDC but on the wheel there is an arrow pointing to the right whit BTC writin on it
Hmmmmm, does the harmonic balancer spin clockwise when facing the engine? Jim
yes it spin clockwise. I really need to leave for work but when I get back im gonna go make absolutely sure that its says btc to the right on the wheel and G A, man would I love it if you would be here!
Whoops, you're correct! It should be at 6° to the right of the TC mark on the timing gauge! VERY sorry about that!! Found a picture with your timing marks on it!! Jim
haha dont worry about it!
I wonder if the timing chain has slipped.
I was wondering about that too, not knowing what work has been done on it previously, he stated that the distributor lines up with the crankshaft pointer on TDC but someone could have retimed it to match. Only sure way to tell would be to TDC number one with a rod to make sure it is actually all the way up on the compression stroke and then check the distributor for number one position.
The clogged exhaust system theory should be looked at too. It would make sense. The muffler could be falling apart internally. We've just about covered everything else. Hope that helps! Jim
I would not be surprised to drop the oil pan and find a bunch of triangular plastic bits in the bottom.
ok so I changed the oil pan gasket last year and unfortunately the crossmember passes directly under the oil pan so I cant remove it without pulling the engine out. tomorrow il go stick my finger in that sparkplug hole and put awire from the battery to the starter so that I can turn the car myself and for the exhaust it look pretty nice from the outside but i can't vouch for the inside... if we get to that point i might splurge a little bit and buy a dual exhaust as its a single exhaust right now.
also i said that it had 30k original miles but im not the original owner. i bought this car from the son of the original owner and he claimed it was the original millage (the car has a 5 digit odometer)
tomorrow im gonna go buy a vacuum gauge
GOOD INFORMATION! ok so installed a brand new distributor so no more guessing and after adjusting it I put a vacuum gauge to the manifold when I start the car it pulls a vacuum of 15 in.hg and is steady at that. when I give I gas dough it drops down! depending on how much throttle I give it, it will go all the way down to 10 in.hg.
Ok so that sounds normal, i would have liked to see 18 at idle but for now we’ll go with that. So now recheck the TDC on number one piston compared to TDC on the distributor, make sure it it TDC on the compression stroke or that will really mess you up trying to set it all up right. One thing I remembered from back then is a lot of the vacuum diaphragms on the distributors were adjustable, so I was wondering if you set the new distributor’s vacuum advance to match the old ones settings. Instructions should have been in the box of the new distributor on how to do that.
I didn't adjust any of the setting on the new distributor and im gonna go and try to find the instruction as I bought this distributor 2 weeks ago and god knows where iv put them. is there a way to tell the difference between the compression stroke and exhaust stroke? im used to having to take a 50/50 but maybe there is a better way
and hem.. you mind if I wait half an hours before doing that? cause I just came back from a drive whit the car and im not too inclined to go put my finger in that sparkplug hole haha
Yeah wait till it cools down, the finger idea works the best then you can use a length of wire to find the exact TDC.
Cover the hole with your finger, not IN the hole. ;)
ok so I went and tested everything. When the piston is all the way up it its indeed on the 0 degrees on the crankshaft and the distributor rotor is on piston number 1 so everything lines up correctly
15 inches of vacuum at idle sounds low to me. Unless you're significantly above sea level. Intake manifold vacuum will be highest at idle speed and will drop off under acceleration (revving the engine). So that sounds normal. I'm at about sea level and my vehicles always pull right around 20 to 21 inches of vacuum at idle. Hope that helps! Jim
went hunting for airleaks and only found one I know have 16 in.hg but now wen I accelerate instead of droping the vacuum increase to 20
I went and looked online and im at about 50 meters above sea level
I had someone took a video of a vacuum gauge if you guys wanna see/know a way a could send it to you
Do you have the gauge hooked up to the same vacuum port as the first time? Carburetor vacuum, that is vacuum that's pulled from above the throttle plates, will increase with engine RPMs. Hope that helps! Jim
There is no way vacuum would increase when you open up the throttle unless it is hooked up to the wrong port as Js says. Just a thought. Make sure the throttle butterflies are not loose.
no, the plates are not loose and I hooked up the air to the an intake on the manifold itself if front of the carburetor
hey! so today since I had nothing better to do I decided to drain the gas tank another time then run the car until it ran ou of gas. put 10 gallons of 100ll gas in it and now iv been on 4 separate -/+ 10 minutes drives and the car runs really well! so the question is, is it the higher octane or the lack of ethanol that is helping the car? also I seriously doubt the the old gas was bad as this is the 3rd time I drained this tank in the last 2 weeks and iv put fresh gas in it everytime but this was the first time I tried pure 100ll gas.
So if it running as it should with 100 fuel then you did indeed get some bad fuel or too much ethanol in it. Your engine was not designed to run ethanol fuels so you may just have to run racing fuel of 100 or better.
yay gonna buy racing fuel at 7$ per gallon in a car that does 6 miles a gallon! no but hem the car used to run fine on normal gas so would you guys know of any component that could have this effect?
A lead substitute should be enough with pump gas. If premium does not work you can use a octane booster but if there is excess pinging I would investigate why. Hot plugs could be the problem or excessive combustion chamber deposits.
ok, im probably gonna have to go and experiment a bit. thank you!
Over advancing distributor. Cam advanced too far. What I would do is pull the valve cover off on number one bank, bring number one up on TDC and see if both valves are completely closed, if they are not then you know you have a cam timing problem. Or if you have an air compressor and a cylinder spark plug adapter you can check for air blowing by the valves on TDC number one after you have blocked the crankshaft from turning. HTH
I was already planning on changing the valve cover gasket as I have a small leak on one of them so il make sure to check this
Did you look at some of the gas you took out of the tank? Any water droplets? If you don't drive the vehicle much that's a real possibility. A good way to prevent water condensation is parking it with a full tank. Even with today's gas you shouldn't have to run leaded racing fuel in it. Unleaded premium with an octane booster should do the trick. The lead in gasoline was put there to lubricate and cushion the valves as they opened and closed. A 73 model should run just fine on unleaded. I had my 70 Pontiac Catalina until 2012. I always ran premium with an octane booster and lead substitute. GM switched to unleaded gasoline capability in 1971. Now that car was fussy about gas! If I didn't put the octane booster in, it would diesel when you shut it off and surge at expressway speeds. In later years I stopped driving it much and it spent most of it's time in storage. I never had a problem with the gas going bad or with water condensation. I always used premium grade (93 octane) and tried to keep the tank full when I'd park it. In fact I now have a 2000 Grand Prix and 94 Fleetwood that I don't drive much. The gas in the Grand Prix is 16 months old and the car runs fine on it. I run it periodically to keep the battery charged and things moving on it. Both vehicles have premium in them with no stabilizer or anything else in the tanks. I think premium keeps better! You might have a higher concentration of ethanol in your part of the country, I don't know. You can put a bottle of Drygas in the gas tank to eliminate the possibility of water condensation and perhaps some gasoline stabilizer when you park it and don't plan on driving it for a while. A full tank is best to combat water condensation. I did some more research on your vacuum gauge reading. 17 to 20 inches of vacuum at idle is normal. A low but steady reading, of about 10 to 15 inches of vacuum is late ignition or valve timing, or low compression. Ignition timing and valve timing are relative to each other in that the camshaft drives the distributor. The crankshaft drives the camshaft via the timing chain. If the timing chain is worn or has jumped one of the ways it will present itself is by retarded (late) ignition timing when checked with a timing light. This is how I found the worn timing chain on my 70 Pontiac. Other symptoms of a worn timing chain are running hot, boiling over when you shut down the engine (heat soaking) , lack of power, and late transmission shifting. The transmission will shift late because the shift points are determined by the vacuum modulator. The vacuum modulator is hooked up to intake manifold vacuum. With the timing retarded the engine will have to rev higher to achieve the needed vacuum for the transmission to shift. Do you remember where the ignition timing was before you replaced the distributor or adjusted the ignition timing? Was it retarded? If so I think further investigation of the condition of the timing chain is needed. In addition to the gasoline information I talked about! It's been a long time since I found myself troubleshooting a vehicle from this time period. Good to refresh the ole memory!! Hope that helps! Jim
ok so i ordered some lead substitute for my gas hope its gonna be enough. the timing on the car was advanced 1 degree before i touched anything and since it is supposed to be at 6 degrees stock it might mean that its was actually retarded by 5 degrees. i also feel like the car runs hot because when i come back from a 10 minute ride and stop the engine you can hear it 'ping' and 'crack'. this is the first ford big block i have ever owned so i dont know if its normal for this engine. it makes me wanna change the water pump and if i do end up changing the timing chain im gonna do it.
and i did not look at the old fuel i simply got it out and dumped it into my camry :)
I assume the Camry has been running fine on the gas from the Mercury. If the timing chain is not badly worn yet the cooling system problems associated with it might not appear until warmer weather. I bought my 70 Pontiac in September and drove it that first winter without an issue. In the spring the cooling system problems started. It would boil over and the "TEMP" light would remain on a few seconds after I restarted it. Like if I drove to the store, ran in for a few minutes, then came back out. As it got progressively worse the transmission became involved with the late shifting. Then I got suspicious and checked the ignition timing. It was severely retarded so I then figured out it was the timing chain. The engine never died and refused to run because of it though. Interesting! Hope that helps! Jim
ok so I was a little cocky today and decided to go for a 15 minute ride! it stalled on me.. so the better gas helped the problem but did not fix it. I guess my next step is to go and check that timing chain of mine.
If this were my car I would buy a new carburetor. They are not that expensive and this would eliminate one factor. Keep the old one for originality. The other thing you need to do is verify the cam/ignition timing to eliminate it as a factor. You may need to pull the timing cover, but this is not that bad of a job.
A phenolic carburetor spacer can help eliminate excess heat to the carb.
yea... im gonna check the timing chain first. the only 'problem' with buying a new carburetor is that the car is 100% original/oem so if I buy a new one its gonna be an oem one (autoline c883a) which is gonna be at least 500$ shipped to me.
I would suggest getting the original carburetor rebuilt. As time goes by many different OEM model numbers are lumped together under the same part number in aftermarket cataloging. The carburetor you get won't be the exact correct one for your car, I can guarantee it! Sometimes it does make a difference! I learned that lesson the hard way with my 70 Pontiac. It would absolutely not run right unless it had the correct 7040060 carburetor on it! Hope that helps! Jim
I have already put a carburetor kit in it and I have the original 1973 shop manual for the car so I adjusted everything to the original specs. im kinda hesitant on getting someone to rebuilt it causse there gonna redo what I did and charge me 200$ for it.
and I dont like having other people work on my cars as I had some pretty bad experience in the past of people cutting corner. even had a guy rebuilt a Buick carburetor for me came back with it non running telling me he could not find the problem. opened it myself and found a piece of drill bit going right through my needle valve and my float (not a joke). I feel like its hard to find competent people who knows how to work on these old cars.
You're absolutely right about that! I feel the same way!! Jim
so what im gonna do is check the timing chain. im gonna go buy a new one because even if its okay im not putting the old one back in! this is gonna be my first time replacing a timing chain so if you guys have any advice/warning to give before I do this I would appreciate it. im probably gonna do it next weekend since im unsure of how long its gonna take me.
Get a good heavy duty timing chain set. You may want to get one that you can index. Timing gears are very accurate and they sound cool if you like that sort of thing.
As you already know what to look for in a timing set the only advise I can offer you is make sure you have a good quality vibration damper puller.
yea when il get the timing set il get a duck foot
hey i decided to remove my egr today and o boy! when i removed it theres are 2 hole going into the egr one of them is partially block by some white residue while the other one is completely sealed off
Ahh Haa you just found the pinging problem, no EGR flow will cause severe pinging.
yay! ok so im gonna have to remove the carburetor plate and clean all of that residue outta there. glad i finally found something.
Make sure the intake crossover is open and not blocked, if it is then the intake will have to be removed and cleaned out either by hand or hot tank.
aww.. its the hole that goes to the intake that is blocked. o well since I have to take the carburetor off it should be fairly easy
I'm beginning to doubt the mileage claim, I've seen this happen a lot but to higher mileage engines, the only time I saw it happen on a low mileage car was a little old lady that only drove it too Church on Sunday and never went over 35 MPH and it had 40K on it.
Also, when you put it back together refer to your shop manual for the vacuum hose routing. The EGR valve vacuum hose should go to a thermo vacuum switch. From there a vacuum hose should go to a vacuum port above the throttle plates. The EGR valve should stay closed when the engine is cold and the throttle plates are closed. With the engine warmed up the EGR valve will gradually open under the increased carburetor vacuum when you accelerate. To test that the EGR passages are clear and the valve is working disconnect the vacuum hose at the EGR valve and plug it. Hook up a hand held vacuum pump directly to the EGR valve and start the engine. Apply vacuum to the EGR valve and the engine SHOULD stall. If it does, the EGR valve is working and the EGR passages are clear. Hope that helps! Jim
Stock pics of Egr spacer to manifold gaskets both 2 bbl and 4 bbl carbs.
yea, no the part I was talking about looks like this. but I just realised that this isn't a factory thing the original owner installed that afterwards
so from what I have read the reason people used to block egr's with these was because they taught it increased hp kinda of how you would remove anti pollution fans. so I guess thats what the previous owner tried to do. o well im cleaning that intake and getting rid of that piece of metal to put that egr back online!
Yep that is an egr block plate, most guys put them on if they were having problems with the egr functioning properly, at the time egr valves were expensive so they just blocked the port and put the valve right back on and this caused severe pinging so the timing was backed off just enough to keep audible ping low. So may find out that the egr valve either no longer works or the internal spring is broken and it pulls wide open when just the slightest amount of vacuum is applied. Back in the day if there was one that just couldn’t get it set right we had a set of washers that fit right inside the egr valve bore and we could restrict the flow just enough to make it not ping and still use stock advance, it was a lot of trial and error to get it right.
I think I learned more these past 2 weeks than I did in the past years thanks a lot to you guys for sticking with me!
It’s rare today that you find anyone that is willing to hang in there when things get a little rough, I want to commend you for sticking with it, most would have given up and just took it to a shop and got their money taken. Keep going and we’ll be as long as they keep the site up.
hey guys! just letting you know I haven't given up, its just been a busy week. i actually realised that i have a sticker on my valve cover that tells me how to check timing and that the stock timing of the car is 10°. tomorrow I am planning on removing the carburetor and intake manifold to go clean all that up and then im gonna try adjusting the timing again. my harmonic balancer only has degrees marks up to 3° so do you guys know how i could accurately bring it up to 10°?
That’s not right. This is the best photo I could find of a mercury vibration damper with timing marks.
this one is very similar to the one I have. just to make sure, the last mark on it is 3 and not 30 right?
you know what the more I think of it the more I think I made a mistake. when I told you give that I brought it up to 5 and it pinged like crazy I think I actually brought it up to 50!
The yellow mark is 0 the first white mark looks like 8 degrees BTDC and the next while mark is 20 degrees BTDC. So it looks like the previous owner has timed it on 8 degree BTDC and that is within the specs. You can go + or - 2 degrees either way. Okay?
I'm seeing 10° BTDC as the correct setting for 1973 V8 429 standard and police package option. The 460 is showing 6° BTDC. From my experience the timing marks will be graduated in multiples of the correct timing setting. For example on my 66 Cadillac it was 5° BTDC so the timing marks were 0 5 and 10. On my 70 Pontiac it was 9° BTDC so the timing marks were 0, 3, 6, 9,12. The sticker you found on the valve cover should give the engine size. It would make sense if the correct timing setting for this engine is 10° BTDC that the timing marks would be in multiples of 2. Hope that helps! Jim
okay yes I understand, each little lines are gonna be 2° because my car is supposed at be at 10°. when I did my testing and I told you guys that the engine would stall if I put it past 5° I was actually trying to put it past 50°! the car is currently set at 10° so my timing is correct. I went and changed my valve cover gasket today I tried to put my engine TDC but the closest I could get was 5° ADTC and with the engine there my valve did not seam to be closed properly I dont know if the 5° that I went over would affect my valve this much
also went I removed my valve covers I found some plastic bits at the bottom
50 degrees of advance. You are lucky it ran at all. Keep at it, you are making progress!
Plastic parts are broken valve guide umbrella seals, big job, you have to bring rack cylinder to TDC and block it there pressuring the cylinder to keep the valves closed and remove the valve springs and replace the valve guide seals, reinstall the valve springs and then move onto the next. The piston must be a TDC to get a proper setting.
okay, that doesn't bother me too much. I am taking a week of next week so il have some time to do that
are these umbrellas universal?
I would remove the heads and rebuild them. Why do a half way job?
because today was the very first time iv removed a valve cover! I feel like going straight to removing the engine heads might be I bit much for me. il go ahead and inform myself on this and if I doesn't look too complicated I might do it.
Yep if you already have the intake off just keep going. I'm afraid that the 30K miles thing just isn't right. Yes umbrella seals were used back then to help with the stock seals from leaking. I did that on my old Ford 400 engine. and it worked.
hmmm well if im gonna go all the way im gonna wait until next week. if I break something or need to order parts I want to have I bit of time in front of me to do so
If you have an air compressor you can use a spark plug hole adapter and pressurize the cylinder. The piston will stay at bottom dead center and both valves will be closed. The air pressure will hold the valves in place on that cylinder while you change the seal. That way there's no need to pull the head. Have you been seeing blue smoke from the tailpipe only at idle? That's a sign of worn valve guide seals. Hope that helps! Jim
yea sometimes when I start the car I have a puff of blue smoke which I know means my engine was burning oil but I didn't know from where the oil came. also I have a compressor and when I bought my engine compression tester it came with a bunch of adapter so I could probably make something work. the thing is I had to move because of what is happening atm and where am at im only allowed to have 1 car on the property so on the week day I have my camry and on the weekend I got exchange it for my mercury so basically I can start working on it Friday night but I have to make sure that its is in working arder by Monday morning so that I can go exchange it for my camry. im telling you this cause I can only do project that can be completed in 1-2 days. when il change the valve seals is there something else I should change while being there I dont mind paying a little extra to make sure everything is top shape!
If you just going to replace the valve seals you can easily do that on a weekend. But if you pull the heads to have the valves done and the guides replace that will take a lot longer depending on how booked the machine shop is.
Pulling the heads is easier than doing the seals on the car (my opinion). All you need is a torque wrench and a shop manual to give you the torque sequence.
hey guys went to pull my distributor to do some adjusting and this huge metal rod came with it what is it?
Oil pump driveshaft. Don’t remove it as they are not suppose to come out, so someone has been in the engine doing repairs and took the keeper ring off the shaft, so now your going to be very careful going back together or you will drop the shaft and it will wind up in the bottom of the oil pan. It won’t cause any problems if it falls all the way down. I pulled an oil pan once and found three of them in the pan.
ok I put it back together and did not hear anything unusual while doing so, so I believe it went back into place correctly
You will know when you fire it up and the oil pressure light stays on while running that the shaft missed the oil pump.
ok went for a ride no oil light so im good. this time when the car stalled I immediately let go if the gas stopped it on the side of the road I went to pump the gas into the carb manually and I could not see anything coming ouf of those jets! the only thing that came out of the carb if a pump it manually is smoke/vapours
You will only see fuel squirt out of the accelerator pump jets without the engine running every time you move the throttle. When your idling the fuel is handled by the idle circuit in the carbs base. The only time you will see fuel through the big jets is revving the engine or a stable RPM around 2000.
so! went and romeved my carburetor so that I could clean the white powder out of the base and hem...…...
You have to look down into the carburetor. You should see gas squirting out when you open the throttle by hand. Do this with the engine not running! In case of an intake backfire you don't want your face near the carburetor!! Hope that helps! Jim
that's exactly what I did and no gas come out of it. it did this seconds after it stalled
So if nothing came out of anything even pumping the throttle then you ran out of fuel, now then could mean you have a bad fuel pump, there’s crud in the fuel tank that the fuel pickup tube collects around the screen and slowly shuts the fuel off, then when the vacuum drops the crud drops off only to do it all over again next time you start driving, or the tank get drawn down by vacuum until the pump can’t pull anymore but I think you said you tried driving with the fuel cap off so if you did then drop that idea. Something we use to do back then was take the fuel cap off, and fuel line before the fuel pump and blow compressed air back into the fuel tank, this would blow off the pickup screen, then install a clear filter before the fuel pump so we could see hoe much crud it caught and replace every month until it started to clear up. Now this is dangerous cause it make a lot of fuel vapor out the fuel spout so make sure there are no chances of any sparks or open flames anywhere around. Be safe and good luck.
ok yea I already tried running with the cap off and it didn't help but! when I bought the car there was a filter installed just in front of the fuel pump that I removed because in my eyes it only added stress to the fuel pump. I dropped my fuel tank a couple of times and there rust in it. I filled it up with white vinegar let it sit overnight and then slosh it around with a piece of chain in it but a lot of rust stayed. in the mean time I ordered a new fuel tank couple weeks ago but I havent received it yet. I also cleaned the fuel sending unit when I put a new brass float on it. when il received the new fuel tank il go ahead and blow air in the fuel line from the engine to see if any sort of debri comes out
also I changed the fuel pump not long ago. and I put the old one in a vice and pumped it manually and it worked. so fuel pump wasn't the problem
Yeah I think you have a lot more rust in there than you think. I once had an old truck that had a auxiliary fuel tank on it and every time I switched over to it the engine would run about 30 minutes then just run out of fuel, and every time it plugged the fuel filter, I took the tank out and steam cleaned it then put some 3/4 inch nuts in there and rolled them around then cleaned it again and even more rust came out, I did that three times and never did get it to clean up, so I put a big truck fuel filter on just that tank now this filter looked like a spin on oil filter but was for gasoline, then I could use that tank, but it would plug up at about 300 miles so I would just change the filter and off I’d go again. Just gave the truck to my ex wife’s son about 15 years ago. He says he still has it but only uses the main tank. So rust can be a real bear to get out of a fuel tank. At least you found a replacement tank.
hey! just received my new gas tank and there is some sort of yellow grease inside the tank. what the best way to remove this?
Try just using some gasoline.
hey guys! jut letting you know I finally changed my timing chain. my very first timing chain, took me 9 hours... the old chain was in great shape so where the gears still changed them anyways. while I was there I went ahead and installed a brand new water pump and a rebuilt alternator.
AALL right? You really got your hands dirty on that job.
the car runs fine i haven't taken it for a ride as i am filthy right now and yea took me a while i am very limited on tool and the only place i had to do this was a gravel parking....
Thanks for keeping us posted.
That's great!! Sounds like you did a good job!! Thank you for the update! Jim
ok so I drove the car around today maybe 50 miles or so and it didn't stall a single time. had a couple of little hiccups but no stalls! what I did since last time it stalled replace the timing chain, alternator, water pump, radiator fan bearing. I also removed the carb spacer as the old one had a hole In it filled with dirt. ordered a new one with the egr adapter on it exactly like the old one I removed.
Getting better, you may have to do a little fine tuning of the carb, dwell, ignition timing and if it has an adjustable EGR valve that too will may need resetting.
hey guys! while searching on the internet I realised that they sell a MAP sensor for my car. when I search trough my manuals I cant find anything about a MAP sensor neither can I seam to find one under my hood. is there I way to know if my car is equipped with one and if so where should I be looking for it? thank you!
Nothing made in 1973 has a MAP sensor. Hope that helps! Jim
Yep way too old for a map sensor, those didn't start showing up until 1979.
ok great. I will stop looking for it! haha.
when coming back from work today I started the car and left it to idle a couple of minute then headed home but the car would try to drown itself everytime I tried to go over 10mph. it kept doing so for a solide 10 minutes and after that it drove fine. my buick does that too if I dont let it warm up for a couple of minute but it dosent need 15 minutes! i installed a 140 degrees thermostat on the car should i change it out for a 160? if that is even related to my problem.
i think i actually have a 160 degree thermostat in the car. but the question remains the same
You should have a 195°F thermostat in there. Hope that helps! Jim
ok, il go order a 195 thanks!
You're welcome. Glad to help! Double check your automatic choke as well. If it's not opening up as it should you'll have an overly rich air to fuel mixture. It may be opening up slowly because of the low temperature thermostat. So replace that then confirm the choke operation. Hope that helps! Jim
yes I know when the car is cold its fully closed and when it is warm its fully open but I dont know how long it takes the choke to do so
hey guys! tomorrow i plan on removing my engine heads. i am planning on replacing the head gasket lapping the valves and replacing the valves steam seals. while i am there is there anything more that i should do. thanks!
If your going through that much then I would have the heads pressure checked, the valve guides replaced and then the heads shaved just to make sure they are flat. Hope there is a machine shop open in your area that can do it. Usually takes a few days in my area. And don’t forget, to use new head bolts, they say you can reuse the old ones but I hate taking a chance.
hmm unfortunately the car has to be back on the road by Monday morning so I cant afford to send the head to a machine shop. I also dont have new head bolts or valve guides on hands. Is it worth it to wait till next week end in order to get my hand on those? also since im going that far into the engine should I change my lifters, springs, push rods, for a couple more buck or should I let them be since I havent had problem whit them. thanks for the input!
If you haven’t had any problems with them then don’t mess with them, just make sure the pushrods are in good shape and cleaned out. Doing any kind of head work requires a machine shop that can mill the heads and replace the valve guides, and other head work, so what you want to do is a very big job, it is one of those projects that takes two weekends to do, one for tear down and heads to a machine shop on Monday to pickup the following Friday to reassemble that weekend. Hope this helps figuring your time frame.
hmmmm I see. well then I think im gonna wait for the heads until I have a place to put the car. thanks again!
Too bad you don’t have a place you can work on it whenever you want, it would make the big jobs less of a hassle.
indeed! used to have a place but got kicked out because of the pandemic. trying to find a house I could buy but in the meantime im keeping myself occupied with the car.
hey guys! so i started to tune the carburetor and boy was that I mistake! I tried setting it to factory from the manuals I have and the car wont even run. I have been screwing and unscrewing screws 1/4-1/2 a turn for the past 3 days and I cant for the life of me get the car to run on itself. I can get it to run (very poorly) if I give it some gas but it just wont idle. even by putting everything back the way it was before I touched it wont work! am I at the point where I should send it to the shop?
So turn the air screws on the bottom all the way in, the back them both out two full turns and start the engine and run it to operational temperature do not exceed 2000 rpm, once it is fully warmed up drop it back down to idle, then slowly turn each screw a half a turn until you achieve a stable idle. Now if this doesn’t work then most like some minuscule piece of varnish came loose when you were trying to reset everything and jammed itself in a passage, it happens so then your choice is to pull the carb off and have to chem dipped and overhauled, if you haven’t done carb overhauling then it would be best to have a shop do it so they can get it setup right for the engine and get the right kit. Bummer man. That might have happened when you shook thing up replacing the fuel tank, who knows what has been laying in the fuel lines and even the pump.
yea I already adjusted the carb that way and it wont run. i installed a carb kit in it last month and made sure to clean it properly. iv rebuilt a lot of small engine carburetors (atv, lawn mowers... ect) never overhauled a full size carburetor but the idea doesn't intimidate me should i give it a shot? if everything fails i can still send it to the shop and yea i changed the fuel tank after the carb kit so maybe i did shake something loose. thank you!
If your not afraid of it the get a gallon of Chemtool and a basket, tear it down and soak it the recommended time, then pull it out and spray it all off and inside all the passages with spray carb cleaner the reassemble it and do the base settings and put back on the engine and see if it will fire off and readjust.
yea i should have a gallon of gunk somewhere. anything unusual that i should know before doing this? or maybe just a tip? thank you!
The only tip I can give you is making sure you get those jets as clean as can be and it goes back together the same as it came apart, the kit diagrams are really quiet good for these Ford carburetors so look at the diagram as you disassemble the carb and note each piece especially check balls and screens.
ok will do. thank you!
Okay, don’t rush and just take you time and you should be just fine.
ok so went to try and buy some gunk/chemtool and the guy told me that the import of these types of product was banned in canada and the best he could offer me was a gallon of brake cleaner.... In the meantime I went to try and check my timing and realised that the timing light wouldn't work on cylinder number one so I pressed on the distributor cap and poof! the car started to run well again. if I let go off the cap the carburetor start spitting fuel and the car stalls. I tried bending the tap on the rotor but it was of no help. So I guess I need to replace my distributor cap and/or rotor? both these parts are less than a month old.
WOW. That must be a cheaply made cap and rotor, I surprised you didn't get zapped when you put your hand on it. I've had really good luck with NAPA ignition products for everyday use. Now I have used ACCEL products for the higher voltage racing coils and they work very well for that. So it all depends on how much you want to spend but they should give you some kind of credit for the bad components if they are only that old. I would not use brakeclean as it leaves a residue. Man they quit selling Chemtool in a can that just sucks. Can you still get Kerosene? That will work as a cleaner but it takes longer, like overnight. Then just use compressed air to blow out all the passages, ports and jets.
unfortunately the place i bought the distributor from has a strict no return policy because of the pandemic.... welp im ordering a premium cap and rotor as we speak! and il wait on these part before touching the carburetor any further. also the previous owner of the car called me out of the blue! said that he really missed the car and he would love to see it one last time. so i told him that the run wasn't running and he told me that he was gonna change the voltage regulator as a mechanic told him this that there was the issue with it but he ended up selling it to me instead. So something else to look into!