rough idle

[nc87k5]

my 87 has the TBI and when I first crank it, the idle seems to be rough, it will idle high then low like it is going to cut off. I have already replaced the idle air control valve but that hasn't seemed to help. Any suggestions?

 

[99firehawk]

the gasket between the tbi and the intake, very very common I must have done 2-3 in the 2 years i had my tbi van.

 

[jpaitala]

On my '89 TBI the problem was the MAP-sensor, after I replaced that the rough idle problem was solved. Cheap part, easy/fast to change.

 

[Thunder]

Have you checked for trouble codes? You should always do that first before you start throwing parts at it.

 

[jpaitala]

Yes, definately check the codes first.
I got no codes when I had that rough idle mystery and changing the MAP-sensor solved the problem.