[V8] No Officer, I don't want to race

[Gene Caldwell]

When my V8 idle began to hunt erratically the problem turned out to be 
the air mass sensor.  But in my case the rpm fluctuation was larger than 
you describe and the car became rather unruly to drive.  The shop manual 
shows limp home mode associated with the air mass sensor. and incorrect 
idle speed associated with the idle switch or air mass sensor.

-Gene


The fault table shows

Andy Schor wrote:

> I have been having some intermittent idle issues with the V8, where it 
> will rev from ~400-800 rpm in neutral (like at a stop light).  The 
> ISV, O2 and knock sensors have been replaced.  This doesn't seem to 
> affect drivability or gas mileage, but this morning I was sitting next 
> to a police car at a light and the revving started up again (I have a 
> Stebro so it is even more noticeable).  I don't think it is related to 
> the following, but mentioned it just in case.  Sometimes it idles just 
> fine.
>
> Yesterday I drove it early in the day and it was fine.  A few hours 
> later I started it, the check engine light came on and it seemed to be 
> in a 'limp home mode'.  I turned it off and back on and the condition 
> didn't change.  I got to the destination, parked for a few hours, 
> turned the key and it was fine.  No CEL, no rough running, no limp 
> home mode.  This morning it was fine (other than the revving thing 
> which comes and goes).
>
> Any thoughts?
>
> Andy Schor
> '91 V8QM
> '91 Avant
>
>