I am not a mechanic, but can do some things. Engine started to miss last week. Has been running excellent.
79 L-82, 59,778 miles. All vacuum lines, ignition wires good. New plugs put in 344 miles ago.
I installed new fuel filter yesterday.
Took plugs out this morning, loaded with gas, after running for 10 minutes. Not oil.
Cannot see any black smoke out of tail pipes. Not burning any oil either, no valve guide leakdown.
Can anyone advise please before I go to Corvette Performance down in Pompano Beach ? Seems to miss more at low speed and idle. At 4500 rpm, not as noticeable, but miss is there. Engine is bone stock, stock Quadra-Jet.
Carb is tight on manifold. Temp is fine.
Any advice is appreciated.
Boatman

Check the vacuum pulloff on the choke. It is the vacuum pot on the pass side front of the carb. It should open the choke plate a bit as soon as the car is started. If not, it will foul the plugs. Fairly common problem. You may also want to do a compression check.

yet another reason to hate quadrajunk..

Ben, that's not fair. I like the Q-jet, but I understand them well. They are a good street carb. No as good for high performance or racing. When I say common, keep in mind I used to work for Chevrolet, and have fixed hundreds of these. As a matter of fact, I just rebuilt mine, and the pulloff is bad, I need a new one!


Boatman, is your pulloff okay?

Ken - I just read everything I could on this carb in the Haynes manual. It shows exploded views, etc.
What is the pull-off ? Where at ? How do you know if it is good or bad ?
About 4 months ago, it did the same thing, miss, etc. It corrected itself after a couple of days.
This time, no luck. Just seems to even out at higher RPM range. With the heavy gas residue on the plugs, after running, does this mean loading up ?
Thanks

The pulloff is on the passenger side of the carb, toward the front. It has a vacuum line going to the front corner of the carb. It has a lever that pulls in to operate the choke linkage, and open it a bit. When the car starts it should pull in right away, and open the choke. Without this operating, it will foul plugs. The vacuum line to the pulloff could be bad as well. If it's warm and the choke is open the pull off has nothing to do with it any longer. But once the plugs are fouled it may take a while to clear, if ever. Very short trips or starting and not allowing full warm up several times in a row will also cause the plugs to load up, with nothing wrong.

The wrong brand of plugs can also cause fouling. If the car is stock, use AC Delco. If not, you may need to use a bit of trial and error to find what works.

|UPDATED|5/12/2004 11:31:08 AM (AZT)|/UPDATED|

yeah im a bit of a quadrajunk hater..

I recognize that overall it was a pretty solid carb used for many years, but in the 14 years ive been playing with cars Ive always had back luck with them..

Its just a personal preference... I personally feel that unless you're restoring or on a tight budget that youll get more headache from a Q-Jet than its worth.

I understand that. It kind of like having a teenager. You have to understand them, and be able to work with them. I have success with the Q-Jet, I'm still trying to figure out my daughter.