mild cam, long tube headers, crossfire injection, aluminum patriot heads, no cats, no mufflers, recent tune up. Idle runs about 700rpms and occasionaly will bog down and stall. other than that no problem restarting and throttle response is great. Any suggestions...............? o ya forgot to mention, bored to a 383

mild cam, long tube headers, crossfire injection, aluminum patriot heads, no cats, no mufflers, recent tune up. Idle runs about 700rpms and occasionaly will bog down and stall. other than that no problem restarting and throttle response is great. Any suggestions...............? o ya forgot to mention, bored to a 383


You want a slower idle speed I take it? It sounds like your throttle bodies are out of adjustment. Try inserting a .0015" feeler gauge between the throttle body and throttle valve, then adjust the screw until the throttle valve just pinches the feeler gauge. Do this to both throttle bodies. Your idle speed should then be around 500-600 rpm.

Typically idle comes down to one of two things. Like TBTR said either TB balancing or the IACs. Those are what two main items that control your idle.

it idles at around 700 which i think is pretty healthy but on occasion it will just kinda bog down and stall, usually when i turn on the AC. but it still on occasion happens without the AC on.

it idles at around 700 which i think is pretty healthy but on occasion it will just kinda bog down and stall, usually when i turn on the AC. but it still on occasion happens without the AC on.


The recommended idle speed is only 450 rpm, so your car is idling pretty fast. The IAC motors are computer controlled and they SHOULD compensate for load changes when they occur. The throttle bodies are known for causing "wandering" idle problems because of excessive housing wear where the throttle shaft goes in them. You can have your housings re-bushed by DCS in Arizona.

Doesn't the idle rpms need to be a little higher for the engines with bigger cams?

Doesn't the idle rpms need to be a little higher for the engines with bigger cams?


Usually, but not always. But the nastier the cam is, the worse the quality of idle at low speeds. I've got a 214/214 Erson roller cam in my '82 and I run my idle at about 600 rpm.

i have a 1985 vette, non crossfire injection, its tune port. when it gets warmed up and driving, when its in gear it idles really hard, acts like its going to stall, and it has a couple of times, but it idles fine when its in park, can someone please tell me how to fix this?

i have a 1985 vette, non crossfire injection, its tune port. when it gets warmed up and driving, when its in gear it idles really hard, acts like its going to stall, and it has a couple of times, but it idles fine when its in park, can someone please tell me how to fix this?


Pull your IAC motor out and clean the pintle (the tip) and also clean the hole that it protrudes into. Over time they both get crudded up with carbon and baked-on oil fumes and then it (they) fail to meter air in properly. You can use Barryman Chemtool or one of the other leading brands of spray-on carburetor cleaners.