Rough Idle on 2003 Pt- Not plugs and wires

[Jungle Jim]

I know this has been covered in the past but my problem seems different. I have changed plugs and wires with no change. I get no error codes on my EBDII reader. I did notice that the problem seems worse with the heater or air conditioner on when the cooling fan starts. Also the O2 sensor output is a sine wave when it is running smoothly but the wave form distorts when the engine stumbles. I don't know if the O2 sensor is just reporting what is happening or is the cause of the problem. Also when the idle is held above 1000rpm it does not stumble. I am thinking it may be the coil or the O2 sensor. Any help would be appreciated.

Thanks,
Jim

[quicksilverdon]

Here's a long read, but might be your problem:
http://ptenthusiasts.org/forum/showt...highlight=idle

and another one:
http://ptenthusiasts.org/forum/showt...&highlight=IAC

since you mention it's worse with A/C, might be the IAC.

[Jungle Jim]

I was out to check and the stumbling problem is not related to the heater or A/C systems. It starts to stumble when the cooling fan starts and continues as long as it is running. I will try the WD-40 trick tonight after work.

Jim

[quicksilverdon]

Good luck, and keep us posted.

[bobs turbo pt]

welcome to the board !! good luck !!

[HighFive]

I read something similar on another site and they stated that it sounded like the EGR Solenoid/Valve. You may want to check that.

[bobs turbo pt]

hey jim, did you fiqure out the problem ??