help with neon only hitting on 2 cylinders

5

Asked by 95neon May 15, 2011 at 09:57 AM about the 1995 Dodge Neon Sport Sedan FWD

Question type: Maintenance & Repair

ok I just bought this neon they said a mechanic put a new timing belt on it it is only running
on cylinders 2&3 if you pull the plug wires off of 1&4 it doesn't change the way it runs at all it
is getting fire to 1&4 plugs already checked that  and is running very rough but after you get
it out on the road and it goes into 2 nd gear it smooths out and then back to rough in 4th  

15 Answers

55

i have a 2004 dodge neon sxt 2.0 . replaced the camshaft posistion sensor and the o/2 sensor..no change. i then changed the spark plugs and wires.. a little better.. then i put a can of pressurized air conditioning compressor oil in the a/c system and no more jerking or running rough.. i hope this helps you or others searching for a fix brizz

5 people found this helpful.
13,485

sounds like either bent valves or burnt valves, injectors on cylinders 1 and 4 move to 2 and 3 see if the oposing cylinders change. Or the coil pack has a crack 1 and 4 run off the same pack and 2 and 3 run off the same pack it is a strong posibility its a coil pack issue.

10 people found this helpful.
1,495

this sounds every much like a coil pack issue that i once had. get some in line spark tester and check it that way. try asking someone on http://forums.neons.org/ they might have a better idea

2 people found this helpful.
13,485

why ask someone on neons.org when i am a certified chrysler tech and own 4 neons?

18 people found this helpful.
60

ok, 2004 sxt. 135,000 miles on it. i have replaced every sensor, all ignition components, fuel injectors, motor mounts(all 4), timing belt water pump and tensioner, fuel pump filter and pressure regulator, catalytic converter, o2 sensors, idle air control valve, air filter, intake gaskets. still have rough idle... still throwing p300 and 303. yes i changed the cam knock and crank sensors, rewired the battery to the starter and the ground to the transmission replaced clutch and speed sensor. you name it i have done it.... any suggestions?

5 people found this helpful.
3,185

I think the better question would be "Why did the mechanic put on a new timing belt? Was it due to be changed, or was it overdue and it broke?"

2 people found this helpful.
60

Matt... I changed it out at 80000 miles because i was doing motor mount... It did not break... But good question. Y did the dude that started this string have it changed...

1 people found this helpful.
3,185

If the belt was changed because it broke, it's probably why the engine isn't running right.

1 people found this helpful.
13,485

CHECK YOUR VALVES...PROBABLY A BURNED VALVE!!!!!!!!!!!!!!!!!!

2 people found this helpful.
85

if if was a burnt valve wouldnt it show up on a compression test? i mean why pull the head off if you dont have to? i just put a head on one we shipped out to the machine shop. rebult the whole motor.but the car seems to have a miss fire and a rough idle. but drives like a bat out of hell and doesnt break up when under a load. if i unplug the injector wire at idel no change, i can unplug both cylinder 1&2 injectors and see no change.... compession is fine, is getting spark, the injecotrs sray out fuel, the computer is sending signal, verified by noid light. so i have fire fuel and spark.... but still have a rough idle... replaced the pcm, the plugs, wires, injectors, comprsion test was good 175 all the way across its a rebuilt head with brand new valves and a brand new cam. new rings on the pistons etc.. all freshly rebuilt... what say you now? 00 neon 2.0 stock with a k7n airfilter manual trans....

6 people found this helpful.
10

This always baffles me on forum comments most of you don't know crap and the other half is chasing parts to fix a undiagnosed problem,ok here's my 37 years of knowledge,first determine if the timing broke and then replaced or maintenance replaced ok if broken than the mechanic did,nt bother to do a compression check I,m doing a 03 Neon 2.0 right now symptoms are running rough And fluctuating to good idle so intermittent idle with check engine light,first cleared the light and waited for it to come back on same codes appeared Multiple misfire cylinder 4 misfire First diagnose coilpack output or for you master mechanics take off the less of your spark plug and lay it next to a bracket or something metal or stick a small screwdriver into the lead and watch for spark or if you want to get real genius take out your spark plug with the wire connected check for spark ok is it working go on to step 2 check fuel again geniuses without tools take off plugs be careful they are brittle of your fuel injector run the car if it runs that is and listen for RPM change no change in idle well self explanatory If either of those tests checkout than we're getting into a more serious problem you will now have to get some tools Step 3 compression test mine was Cylinder 1 141 #2 140 #3 87 #4 70 Whoops there's the problem 2 Cylinder are average 3 and 4 are bad ok you no longer have to spend money on useless crap Now check your timing belt and see if your marks a Line up this should tell you the problem yes your tools are now required to check for these marks however if for some reason your marks line up then during your puzzling moment of disparity your conclusion should be that you either have a burnt valve or a bent valve or believe it or not a massive amount of carbon around the stem and seat area of your valve and isn't closing far enough to get complete compression you guessed it Head removal and off to the machine shop you probably need a new head gasket anyways Moral of the story is proper diagnosis,keeps you from guessing and asking a lot of gee could that be it questions as you get a lot of useless answers

1 people found this helpful.
20

Check coil pack it shares cylinders 1&4 and2&3

2 people found this helpful.

I have a neon it's running on 3 cylinders Spark plugs are good plug wires are good injectors are good IT'S THE COIL PACK!

I have an 2002 didge neon and i replaced the head gasket and set the timing and all and went to go start it up and bam i ran rough as hell I figured out the problem right away start with the two vacume lined coming off the valve cover if you un plug the from the intake and trottle body and plug both both lines with your fingers and and the take your finger off the line that is on the back of the valve cover and keep the on plugged that is hooked the pcv valve on the side of the valve coverand it started to idle down replace the pcv valve and the if i dont pull the air cleaner and lay your throttle body down and put your air cleaner filter on These cars always had trouble with rough idle due to high air cleaner with short ribbed tubing

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