i have 85 gsl and after the car is fully warmed up it idles at around 1000 RPm in neutral and then drops to about 250 rpm almost to a stall and was just wondering what the cause could be and if it could be fixed?
cheap?

 

sorry it's 12A CARb

 

try uping the idle.

 

Nlc1179 how do i go about doing that? im not smart to this stuff plz bare with me!

 

Many (if not most) of the problems with 12a carbs are a result of vacuum leaks. Do a search on this forum on "vacuum leaks", and you will get several ideas on things to look for.

 

ok i might have figured out the problem it might try upping the idle! but i think my BAC valve is bad! and i need some good places to go to find it i can't seem to find it on searching the net!
Thanks for all the responses

 

You're saying it stalls at idle when you try to start rolling? Or does the idle change spontaneously? Is your emissions control intact or removed? Does your choke work?

First, make sure the fuel filter is good. Just replace it, about $3. Then look for vacuum leaks. The big hose from the back of the intake manifold to the #2 AAB is a frequent cause of trouble. You can let the car idle and spray all around the hoses and carb with carb cleaner. If you spray somewhere and the idle changes, you've found a leak.

 

yes sometimes it just recently started it used to idle when warm at 850RPM and now it goes from about 850-almost 300 almost sounding like it's going to stall!

SLashdawg00110 im not sure what you mean by #2AAB?

 

so it goes from 850 to 300 spontaneously? Is it when the choke opens? When teh engine is finally warmed up? After a hard run? When you push on the brake pedal? Is there any noise when the idle drops? Does the idle bounce back up after it drops?

#2 AAB is the antiafterburn valve located at the top of the carb, rear passenger side. To me, looks like a brass top hat with two nipples on each side, one large and one small. The large nipple on the rear connects to the rear of teh intake manifold. Common source of vacuum leak.

 

no it';s when the car is fully warmed up! it kinda is better after a hard run at a constant 3500 Rpm then when i start it up after sitting for oh 1 hour it dont do it as bad it goes from about 850-550 spontaneously! and then gose back and fourth THe #2AAB what does one of those usually run?

 

well thanks SLashdawg i have found my problem it is a vacum leak! im in the process of fixing it up!