Carb problem

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Nov 28, 2005 | 07:50 PM

BARRY L-48

Thread Starter

Racer

Joined: Jan 2005

Posts: 307

Likes: 2

From: McCordsville Indiana

Carb problem

I have an 80 L-48 with a rochester quadrajet and after driving it the idle speed always has to be readjusted,I must kick the gas pedal down a time or two to get it to idle properly.Today when I took her to work,instead of kicking the gas pedal,I removed the air cleaner expecting to find the choke not fully open but it was fully open,it is electric choke,I did purchase a carb rebuild kit for a project this weekend,will rebuilding this eliminate this problem or should I look elsewhere for the problem,I do not know when or if the carb has ever been rebuilt so it can't hurt to do it.Any help would be much appreciated!

Dec 3, 2005 | 06:34 PM

BigBlockk

Drifting

Joined: Sep 2004

Posts: 1,959

Likes: 1

From: North Bend Ohio

First you need to get the base plate off of it.

In the photo above the well plugs are the four red dots at the top. The plug to the left (accelerator pump well) leaks sometimes as does the fuel inlet plug at the bottom of the picture. It's a good idea to do them all while your doing. These are plugs with soft metal peened into the seams. They plug access holes used for drilling passages when the carburetor was manufactured.

By the way, if you're going to be working on this carburetor you really need one of these.

http://www.ecklers.com/product.asp?p...&dept%5Fid=224

BigBlockk

Later.....

Dec 3, 2005 | 06:35 PM

BigBlockk

Drifting

Joined: Sep 2004

Posts: 1,959

Likes: 1

From: North Bend Ohio

Sorry, wrong thread.

BigBlockk

Later.....

Dec 3, 2005 | 07:20 PM

Kalway

Safety Car

Joined: Dec 2004

Posts: 4,071

Likes: 0

From: San Diego CA

Shouldn't be too hard to find the electric choke parts. Check summit, they have just about every part of a q-jet you'd ever need.

Dec 4, 2005 | 06:56 AM

kb2fzq

Burning Brakes

Joined: Aug 2005

Posts: 1,126

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From: Hudson Falls, N.Y. 76 Vette Modified L-48

If the choke was open, I'd say the electric choke was working fine...sounds to me like you have some sticky linkage...I had that prob with mine when I put it back in service (wired the electric choke)...maybe some carb cleaner, and look to see where it's locking/jamming up, doesn't take much to cause that problem..I ended up loosening the shaft screw to the fast idle just a hair...all better.

Dec 4, 2005 | 08:13 PM

plasticchevy

Advanced

Joined: Sep 2005

Posts: 62

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From: Gardner Kansas

If your not sure if the carb has ever been rebuilt then it probably would be a good idea to do so... The before mentioned rochester rebuild manual is an invaluable tool... The book almost exclusively focuses on the Q-Jet and I really don't think it could be anymore detailed... Well worth the 15-20 bucks when considering the time it will save...

I got mine at Amazon for 11.99

Good luck

Dec 5, 2005 | 12:35 PM

Boofers

Drifting

Joined: Nov 2002

Posts: 1,665

Likes: 1

From: Ontario

Quote:

Originally Posted by BARRY L-48

I must kick the gas pedal down a time or two to get it to idle properly.

One possibility for this problem could be that your primary throttle plate shaft holes in the carb baseplate could be worn. This causes your primary throttle plates to be stuck slightly open because they end up being 'twisted'. The fix for this problem is to have a carb repair guy install bushings in the baseplate to eliminate play in the shaft.

Another possible cause - IF your air cleaner is an aftermarket drop base aircleaner what can happen is bottom of the air cleaner can hold down the top of the accelerator pump lever, causing your throttle to stay open. Look on the bottom of your air cleaner for wear marks.

This may help you figure it out -

The ultimate QJet troubleshooting paper by Lars

Dec 5, 2005 | 12:38 PM

Stewart's74

Safety Car

Joined: Aug 2000

Posts: 3,943

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From: Florham Park NJ Port Credit Ontario

Another possible cause - IF your air cleaner is an aftermarket drop base aircleaner what can happen is bottom of the air cleaner can hold down the top of the accelerator pump lever, causing your throttle to stay open. Look on the bottom of your air cleaner for wear marks

This is what I was going to suggest....might as well start with the easy and free fixes first....