Can any of you pontiac gurus tell me what this is for on my 1972 grand prix 455 motor.

205

Asked by Wedoe Mar 21, 2012 at 01:07 PM about the 1972 Pontiac Grand Prix

Question type: Maintenance & Repair

Iam getting ready to put a Edelbrock Thunder Series Carb on my car and I was woundering if this could
be taken off. I well post a picture of it. Thanks, Keith

14 Answers

6,095

that's a vacuum dashpot and yes you can unhook it . I am wondering why you want to nix the Q-JET ? The pontiac version flows 713 CFM and it will lend you the best mileage of any carb around providing it's properly tuned .... Just a thought ... PBN

1 people found this helpful.
6,095

since this is a 455 that particular carb flows 800 cfm !!!

1 people found this helpful.
205

I have had it rebuilt two times and it seems like I cant find someone to do it right. It is leaking fuel again and it seems like I cant get someone to adjust it right. I think I well but this new one on until I find someone to rebuild it right. Thanks for your help.

1 people found this helpful.
205

This is after I had it rebuilt. What do you think. Should I find someone that really knows what they are doing and does anyone know someone ho can rebuild it right. Thanks, Keith

2 people found this helpful.
6,095

where are you located ? I'm in central Illinois and I AM THE QUADRAJET GURU OF ILLINOIS INDIANA ,OHIO AND IOWA ! BTW , where is it leaking fuel from ?

1 people found this helpful.
205

Peter, I live in Branson MO. I use to live in Godfrey IL. I am not sure where its leaking from. It looks like it is leaking from the bottom but I am not sure. You can sure smell the gas though when you pick up the hood. Heres is another picture of the carb.

1 people found this helpful.
205

Peter, the number on the carburetor is 7042262 J1 XD Do you know what size carburetor this is with this number. Thanks keith

1 people found this helpful.
6,095

Im pretty sure it's an 800 cfm but you can tell just by looking down thru the primary( Small) bores . if there's a small bump at the 11:00 o'clock position onthe left side and one o'clock position on the right side then my friend you have an 800 cfm unit and it's a dandy ! Most people shelve or junk the Q-jet because they fail to understand it's relative complexity .. BUt they really are a work of art and damn hard to beat if properly modified to your specific application ... If you can find DOUG ROE'S book titled Rochester carburetors ,you yourself can become the carb Guru ... THIS book contains EVERYTHING you need to know about the Q-Jet's tuning , operation , QUIRKS and where to get the right parts ..Doug Roe was back in the day an engineer for rochester carbs (hint ,hint ) SADDLY it's been out of print for a while but you might try AMAZON .COM . for your application I would first try tuning the secondary side (it's easyest ) this is of course after you fix you fuel leak ... can you tell me exactly where it's leaking ? Is it the fue filter l nut at the fuel line connection or is it flooding every time you shut off the engine ? I'm glad you got this on here ,I haven't had a Q-jet Query in a long long time !!! Let me know what your exact problem is and I will help you get your Q-jet back on the fast track ... OK man ? PS even the people that HATE me call me the carb guru !!! PBN

1 people found this helpful.
6,095

Do you have to crank it quite a bit after it sets all nite to get it started ? IE is the fuel bowl empty the next day ? If nothing else I guess you could ship it up here and I could fix it ... let me know

205

Peter, It looks like its leaking at the fuel filter nut at the fuel line connection and a gasket leak. It does not flood every time I shut off the engine but every once and a while. Well look at it a little more in the morning. When the car warms up to temp. it runs strong and does not starve for gas. Thanks for all your help. I think we well get this Q-jet back on the fast track real soon. Thanks Keith

1 people found this helpful.
6,095

yea baby !!! don't worry If nothing else I can send you some secondary metering rods to try out and see if we can make your baby a little stronger .... AHHHH HAAAA !!!

6,095

and thats a pretty good looking baby you got there ! I haven't seen a RED GP in a long time !!

18,245

I'm loving this thread, and thanks for the tip on the Q-Jet book. I haven't looked yet but I'm sure it won't be hard to find one on E-bay. I agree the Q-jet is an awesome piece and is usually overlooked because people won't take the time to understand it. I'm looking forward to hearing how this project turns out. I hope Wedoe will let us know.

6,095

I'm sure he will !!! AND your welcome . it's really an excellent book too !!!

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