87 Iroc Idle problem, help, advice??

[Irocnroll]

I have a 1987 Iroc 5.7 350. When I start my car in the mornings it fires right up but then seems to have a hesitation to the idle as if something is trying to choke the motor out. Sometimes it will turn over, rough idle a few times and die and sometimes it will not. Thinking it was the fuel filter I had it changed out but it has not helped. After the car has warmed up I can press down on the gas as it sits in park and feel and hear the hesitation between 600 to 1000rpms, anything above this range and it seems fine and I can not feel a hesitation but when the idle returns to around 600 I can sense something is not right. On the road the car runs fine without any missing and only seems to be having a problem with the idle when it is in park. I had a friend of mine who is a mechanic hook it up to check for any error codes and it showed nothing. Can a sensor be bad without showing an error code? Could it be the sparkplugs? Any help or advice would be appreciated, thanks for your time.

[speedy15464]

my buddy had and 89 iroc doing the same thing he replaced the tps throttle positioning sensor and now its fine . try that hope it works

[ct91rs]

Originally Posted by Irocnroll

Can a sensor be bad without showing an error code?

Yes, it could.