'90 Cutlass Supreme 3100 PFI

[Joe Boucher]

What did the scan tool say about the tmperature signal?  Was it in the right
range?  Could the engine heat soak, then the temp signal tell the computer
the engine is much colder than it is and pump in a mixture for a much cooler
engine?

Joe Boucher
'70 RS/SS Camaro  '81 TBI Suburban

Matthew B. Watts wrote:

> -----Original Message-----
> From: mccabet at mediaone.net <mccabet at mediaone.net>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Wednesday, February 25, 1998 12:46 AM
> Subject: '90 Cutlass Supreme 3100 PFI
>
> >I need some help diagnosing a problem with a '90 Cutlass Supreme with
> >the 3100 PFi engine.  The scenerio goes like this:
> >
> >Engine starts and runs when cold.  It will re-start as long as you don't
> >let it sit for a few minutes.
> >
> >Once it has sat, the engine will start and then promptly die.
> >Depressing Gas pedal makes it worse (Dies quicker).
> >
> >Checked fuel pressure - 42PSI Key On Engine Running, 44 Key On Engine
> >Off.
> >
> >Scantool shows no error codes in system.
> >
> >TPS checks good with no fluctuations noted.
> >
> >I know chrysler systems better than any other so I am lost on this one.
> >A shop claimed the injectors was bad a quoted $1200 to fix.  I don't
> >think it is injector related since the engine will start and run when
> >cold.  By The Way, the engine will keep running and will even restart as
> >long as you don't let it sit.
>
> This is only a WAG but my '94 Dodge Ram started doing the same
> thing just a week ago--right after it burned a whole in the exhaust
> upstream of the cat-converter.  I'm guessing that air is getting into
> the exhaust at idle and messing up the oxygen sensor once the
> unit goes into closed loop mode.  I haven't began any repairs as
> yet so I don't know if this is the real problem, but you may give it
> at least 10 minutes of looking over before trying something
> totally off-the-wall.
>
> The good news is that my wife was driving it at the time when it
> started sounding like a street-rod, so I'm off the hook regardless.  (-:
>
> Hope this helps...
>
> Matt Watts
> University of Utah
> Formula SAE Racing
> _________________