Idle Problem

[Blt4ice]

Problem: In Neutral Idle stumbles, In drive, idle occasionally is very rough, so rough my head hits the glasstop.

So far I have replaced cap, rotor, plugs, wires, PCV, Oil, oil filter, and TPS sensor. The car still has the same syptoms.

I have a fuel filter waiting to go in, and will be getting a fuel pressure gauge and new Timing light.

This is a 1990 vette with 130k miles on it.

Any other suggestions? or previous problems you have had like this?

 

[spyysee]

any trouble codes?

 

[RedRagTop]

Drop that fuel filter in, it should not be related to your spark now after changing all those parts. If no codes it sounds like fuel...

 

[Tuna]

Did you clean the throttle body - especially the Idle Air Circuit?

 

[Blt4ice]

No fault codes stored. I sprayed out the Throttle body before putting any of the other parts in.


So it sounds like I am on the right track now, I'll drop in the new filter.

I do have one concern, sometime last year the car would not start, and it ended up being a blown fuse on the fuel pump. I replaced the fuse and the car started right up. Do the fuel pumps usually drop in performance, or are they a either work or not work type of part? I was begining to wonder if there was low fuel pressure, but before I invest 30 bucks into a pressure gauge I want to make sure I am on the right line.