[Shotimes] Re: Idle Changes when Depressing Clutch Pedal

[Alan Fanning]

Does the cruise control work? If not, it might be the variable speed sensor
(VSS).  That's just a WAG tho'.

There is a knock sensor, in the valley btwn the cylinder banks. Kind of a
PITA to R&R. Costs about $30 IIRC.  I have a spare if you want to try one -
replacement didn't make a difference on my car. There may be a diagnostic
for the knock sensor in the Probst book on EEC-IV systems - I don't know
where mine is at the moment.

    Alan 

> 
> Folks,
> It has been years since I was on the SHO list, but I have run into a very
> interesting problem with my '89.  It has begun to idle higher that normal
> (1500 rpm) and takes longer to settle down to normal idle (800 rpm) when
> coming to a complete stop, engine warm or cold.  It has a new IAC valve and
> TPS.  Another oddity is that when I depress the clutch pedal, it idles back
> down to 800 rpm - like taking it out of gear when coming to a stop.  This is
> very repeatable and there is no CE light at all.
> 
> Another problem is that I have spark knock, when engine warm, from 2000 to
> 3500 rpm under WOT or slightly less than WOT.  I have had the engine
> decarbonized at FPS in ATL recently to try to correct the problem, but that
> has not.  Could it be the knock sensor?  Is there a knock sensor?
> 
> Any help with these two problems would be greatly appreciated!
> 
> Best regards,
> Tim Waters
> 89' Lt. Titanium