[89suburban350]

ok so my mechanic pointed out to me today that my idle is way too high is there a way i can adjust it? it is a 1989 chevy suburban 350 5.7 tbi

 

[84fiero123]

Idle in the TBI is controlled by the computer, and other things. Not real familiar with these newer fuel injection systems so I will leave it for more informed members.

 

[89suburban350]

ok well my mechanic said its most likely the throttle body gasket and if he's not right eh 2.99 from autozone...

 

[TrailLeadr]

It should idle around 700-900. What's it at?

 

[89suburban350]

idk exactly but its really high

 

[dwill3015]

My 87 TBI 350 idles high because the main housing gets worn out where the main butterfly shaft runs through it so it hangs up and keeps the throttle cracked open a bit causing the high idle. If I quickly pop my foot on the pedal and let it pop up it will idle down to normal. I have been told you can have it worked over for a couple of hundred clams but I may just go with a aftermarket TBI instead.

 

[88 Dually 4x4]

Love The Beast

It could also be the idle air control (iac) motor. When its idleing high shut off truck for ten sec. & restart it if the idle is down good chance thats it (about $50)