85 idle issues

[patrickj]

Hi all having high idle issues that come and go.I set the idle with iac dis-connected,set the tps at .54 volts idle goes down to about 550 and when i shut it down and re-start it runs up to about 900-1000 hunts around a bit and then drops a little.Sometimes it will correct itself briefly and then it idles up again.Anothe thing that bothers me is the idle and the timing do not change when the connector is unplugged.Brand new motor all new sensors.Throttle screw backed all the way out and push back on the linkage with no effect.Any ideas????

 

[boomdriver]

Hi all having high idle issues that come and go.I set the idle with iac dis-connected,set the tps at .54 volts idle goes down to about 550 and when i shut it down and re-start it runs up to about 900-1000 hunts around a bit and then drops a little.Sometimes it will correct itself briefly and then it idles up again.Anothe thing that bothers me is the idle and the timing do not change when the connector is unplugged.Brand new motor all new sensors.Throttle screw backed all the way out and push back on the linkage with no effect.Any ideas????

could be the IAC. They get dirty with carbon and fail. Cheap to replace.
Air leaks come to mind. Idle being up to 700-900 initially then settling down to 600-650 after warmed is normal. The vac lines have to be routed and connected right. The vac is different for different things.