C3 Code "5" (California) Q-Jet

[Paul L.]

This is perhaps a silly question but here goes. I have had some Q-Jet problems lately with my 1974. The carb is #7044206 (350/195 automatic) sourced from NAPA when I bought the car in 2008. It has always ran a wee bit rich and that annoyed me despite my efforts (not well versed) to correct that situation. Something was just not "right".

The car arrived here in Canada via TN but most of its life was spent in CA. The carb on the car in early 2008 was a #7044526 (from a Monte Carlo?). The engine is an NOM 350 and carries California Air Resources Board (CARB) certification on the door jamb. The ...526 was in need of repair; hence my purchase of a replacement from NAPA. It was recently rebuilt but sitting on a shelf in the basement.

Given problems with the ...206 I popped the .526 on. Darn thing runs perfectly! And even on cold start-up (rich condition) it throws much fewer fumes than the ...206. So it will be my choice for summer 2010.

Q1 - What is a CA Q-Jet?

Q2 - I cannot find a carb number in the Black Book for a 350/195hp automatic CA car. Was the L-48 automatic sold there? If yes, is it possible that the ...526 was the carb of choice?

I appreciate your views.

[William C.]

Re: C3 Code "5" (California) Q-Jet

1n 1974, there was not a "california" carb for the base engine configuration, so your 7044206 would be correct. I believe your problem with the 206 is likely more related to the quality of the NAPA rebuild than the the 7044526 is slighlty different, but the actual performance difference between it and the 206 should be insignificant, as they are both speced to 1974 regulations. I'd suggest having a really good Q-jet restorer look into the '206 if it is dated correctly for your car, if not I'd likely look for a "correct" 206 and start over with a competent rebuilder.

[Paul L.]

Re: C3 Code "5" (California) Q-Jet

Thanks Bill. I have read of NAPA and other chain Q-Jet rebuild issues but I did not believe such reputable firms would be negligent. Lars has made that point repeatedly. But....live and learn. The ...206 is in the hands of a local Corvette C3 person at the moment for an examination of its problems. He did the ...526 rebuild and is very good with these old carbs.

[Joe L.]

Re: C3 Code "5" (California) Q-Jet

Thanks Bill. I have read of NAPA and other chain Q-Jet rebuild issues but I did not believe such reputable firms would be negligent. Lars has made that point repeatedly. But....live and learn. The ...206 is in the hands of a local Corvette C3 person at the moment for an examination of its problems. He did the ...526 rebuild and is very good with these old carbs.

Paul------


Over the course of the last 40 years I have yet to find a commercially rebuilt carburetor that performed like a new carburetor. I have rebuilt my own cores, owned from new, and had them perform essentially like a new carburetor, but I've yet to find a commercially rebuilt carburetor from an unknown-source core that was as good. I've had these carbs APPEAR like new carburetors, but they did not PERFORM like new carburetors.

The above does not include specialty rebuilt carburetors from small, specialty shops. I have only used that service once and the carburetor has never been run so I don't know how well it will perform. However, it was rebuilt from an owned-since-new core of mine and the rebuilder was one of the best specialty shops on earth for Q-Jets.