olov

Can anybody tell me what the idle rpm should be on a Caprice 1991
with a 5.7 eng. 9C1 police package.
To me it seems a little bit high,aprox 1100 rpm in park and 850-900
in gear.

Countilaw

In park it should be about 800 and in gear should be about 650. It should increase when you turn the AC on. Check your idle adjustment screw and make sure the carb actuator returns and rests on the stop. You may just need a new return spring.
Countilaw

RABarrett

You may be on the way to a vacuum leak developing, adding the extra air to defeat the idle control. Carefully check all hose routings and check the intake. Ray

ChevyCaprice350

yea, i have the same problem with the idle stuff, When cold the idle goes from 300-6or 700, and i have had new 02, check all vacums(i think all), but does anyone have any other ways of getting this 90 caprice, 350 to stay calm?

ChevCaprice350

Hey, i have the same problem with the idle jumpin like that. What i did was take some carb cleaner and spray it along the intake seal. if the idle calms for about a second ot two. then where ever u just sprayed is where it leaks. And i have the 5.7 1990 pol. thats where i found my leak. i plan on puttin some filler there untill i get my new parts when i build up the whole motor. but give that a try.