High Idle Question

I changed out my TPS on my 90 and the high idle issue is still present. It idles fine until it gets all warmed up. And if I let the clutch out a little at a red light or something to slow the motor down to about 700 it will stay there till I drive off and stop again then its back to 1100. Is there a ported vacuum switch anywhere that opens up at operating temperature? My theory is that there is a vacuum leak down the line from a switch that opens after operating temp has been reached. Or is my IAC just crap?

Thanks

Ecarlcl

High idle only at warmup is usually some vacum leak than expands from the heat. On my xj and many others I have heard about on the internet forums it is often caused by loose intake manifold bolts. I tighten mine once a yr to keep the idle down. Tighten the bolts starting from the middle bolts working out to the ends. The ones underneath are the hardest to get to. Fixed my warmup high idle. Good Luck. Greg

dosent the tps need to be set through the obd?

GPRSDLYT said:

dosent the tps need to be set through the obd?

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Non-ODB ECU. These are not ODB compliant. You can set the TPS with a multimeter on 87-90 models.

Greg Smith said:

High idle only at warmup is usually some vacum leak than expands from the heat. On my xj and many others I have heard about on the internet forums it is often caused by loose intake manifold bolts. I tighten mine once a yr to keep the idle down. Tighten the bolts starting from the middle bolts working out to the ends. The ones underneath are the hardest to get to. Fixed my warmup high idle. Good Luck. Greg

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Thanks, I was planning on putting a new header on it this spring so I'll throw a new gasket and everything in and we'll see if that works.