Idles at 3K RPM!

[Yousuf Khan]

My 2000 OBW with 5MT has recently started fast idling at 3000 RPM. It
does back off a bit when going to slow idle, but only down to 2000 RPM.
This only happens when the engine is cold. Starting the engine when its
warm results in regular idle rates 1.5K RPM fast and 1K RPM slow.

I had a similar situation a year or two ago, and back then I think the
problem was with the throttle position sensor. However, back then it
would do this all of the time when starting up (it would go down after a
few minutes of driving), warm or cold engine. This one only does it when
the engine is cold. Previously it would only idle at 1.5K fast and less
than 1K slow when starting cold.

Any ideas what could cause this? Oxygen sensor? Something else?

Yousuf Khan

 

[Jim Stewart]

My 2000 OBW with 5MT has recently started fast idling at 3000 RPM. It
does back off a bit when going to slow idle, but only down to 2000 RPM.
This only happens when the engine is cold. Starting the engine when its
warm results in regular idle rates 1.5K RPM fast and 1K RPM slow.

I had a similar situation a year or two ago, and back then I think the
problem was with the throttle position sensor. However, back then it
would do this all of the time when starting up (it would go down after a
few minutes of driving), warm or cold engine. This one only does it when
the engine is cold. Previously it would only idle at 1.5K fast and less
than 1K slow when starting cold.

Any ideas what could cause this? Oxygen sensor? Something else?

I'd still suspect the TPS. They can go
bad and they can become intermittent.

 

[YKhan]

I'd still suspect the TPS. They can go
bad and they can become intermittent.

Yeah, I was afraid of that, I've already replaced it once maybe a 1.5
years ago.

Yousuf Khan