1988 sierra 5.7 engine c/k, I have a fast idle, I have replaced the IAC and the EGR. Need a direction to go next.

Jim

 

Probably the tbi gasket....spray a little b-12 around the base while she runs...BE CAREFUL THOUGH...The stuff is flammable as hell!

 

Thanks Much will give it a shot, is there anothor name for it, can not find b-12

Jim

 

I believe he is thinking if you just spray something around the gasket area to see if the engine speed changes - any carb cleaner should work .

 

thanks birddog, having a senior day.
jim

 

Yes,carb-spray..B-12 is most popular..but most any brand..again,CAUTION..that stuff is close to pure ether.. the idle should change and you'll hear a sucking sound if the gasket is blown.
Fairly common on Tbi trucks

 

ok thanks argon, you guys have me straight now, love this internet
Jim

 

replaced tbi gasket, this solved my problem
Thanks
Jim

 

Cool...glad she purrrs now!