[jons1946]

I jsut recently purchased a 1979 Corvette with the L-48 engine. It is a California car and starts fine and idles at 1300 RPM till warmed up. At this point the idle drops below 500 RPM and the engine stalls. I have checked most vacuum lines, put in a new air filter and fuel filter. What could the problem be?

[fishslayer143@yahoo.com]

have you tried turning the idle adjustment screw to increase idle speed? its on drivers side of carb .. while the choke is on, the fast idle cam on the passenger side ,sets idle speed , when it goes off, the idle falls. ..

[jons1946]

I had my brother in law adjust the idle (on the drivers side) over the Xmas holidays while I kept the RPM's up. This seemed to help for a while, now it's back to the initial problem. Note, I also added Sea Foam to the gas tank which I hoped would clean the carb. This car sat in storage for 12 years and the owner took it out of storage and started working on it about 2 years ago.

[jons1946]

Can the fast idle cam be adjusted (on the passenger side) and what should I look for? Any help would be appreciated.

[bpassmore]

If it is a Q-jet it probably has a bad float, saturated with gas causing the idle to go too rich and die. That is probably why the increase in idle speed did not hold.

[fishslayer143@yahoo.com]

if it sat for 12 years, that carb is probably in need of a thorough cleaning and maybe a rebuild... Seafoam just won t do it

[jons1946]

Thanks for your responses. I kinda of figured that the carb. has issues. This is my fourth vette. I had a 74, 70 and 80 prior to this. The 74 and 70had a 454. The 80 had the L-82. I never had problems with any of he previious cars but the 79 I just bought has a ton of problems (mainly vacuum and electrical). I'll probably just buy a rebuilt carb and go from there. Summit sells a rebuilt for $299 which I hope will work on this car since it is originally a California vehicle.

[bluedawg357]

If your concerned about the original carb, email lars at v8fastcars@msn.com, he will send you his papers on rebuilding the quadrajet. He'll even rebuild it for you for a fee, running it in on a test engine and wide band o2 to ensure that its set up right. Would cost ya less than buying a new one.