[s-cars] miss at idle

[Matthew Russell]

Hi guys- Update #4... (longish)

Had some good emails off list with Paul Gailus... between that and the  
info y'all have shared previously, I limped the car home today on 4  
cyls where it now sits in the garage waiting for parts. I wanted to  
detail this for the next person and general sharing of knowledge.

Paul and I speculated that the CPS failing didn't make sense symptom- 
wise with what the car was doing when it wouldn't restart after the  
initial diagnosis of a bad #2 coil.  He thought that perhaps the ECM  
was still trying to fire the #2 coil and if it was worsening, or had  
an internal short or short to ground through bad wiring - that a  
breaker somewhere was getting tripped.  thus, the car would idle for  
those few seconds, die... and then not immediately restart until the  
breaker reset itself.  It just decided to up and die when I was  
driving it when I shouldn't have been...

So after checking fuel pressure today, I disconnected the voltage  
supply from the ECM (one of the 2 white (?) connectors on the firewall  
and checked for resistance to ground.  Some continuity was present  
where it should have been OL on the coil #2 lead.  So I disconnected  
the supply lead from the connector and taped it up out of the way.   
The car fired up, still running on 4, but running... and I was able to  
nurse it back.

Good things to share.  Thank you Paul, Steve, Dave, Bob, JC and Calvin  
for your ideas and help.  I hope this info will also help someone else  
down the road. I learned a bunch.  Will be back on the road by the end  
of the week.

Till then, it's the wife's 1998 V70. nice car, but man... not an audi.  
Boy do they squeak and rattle something fierce.
8-)

-Matt, CO
92  s4



On Nov 15, 2008, at 9:22 PM, I wrote:

> Hey- Update #3...
>
> well, she now sits in a parking lot about 3 miles from home.
> I was gently driving home after what I hoped had been productive as  
> far as figuring out this issue and 10 minutes down the road, tach  
> went to 0, oil light flashed, and engine stalled.  Yikes.
>
> checked oil (full) and attempted restart.  Turns over more times  
> then normal, no catch.  let it sit for a minute while i pulled  
> codes, only found one for 2212 Throttle Potentiometer which I'm not  
> convinced i read correctly.  I need to recheck tomorrow.
> Attempted restart, engine caught and idled for 15-20 seconds? then  
> died again. Hmmm.  This seems different than the first issue of a  
> coil going out.
>
> So i'm thinking new problem in addition to original? or related?  I  
> need to recheck for spark and fuel in the morning and see if  
> anything else has changed, as well as blink out any codes.
>
> Oh, and I had a bottle of cold water with me, so i poured it down  
> near the cam pulley in case the CPS is on the way out, and i thought  
> maybe that (the water) made a difference, but now i'm not so  
> convinced.  As I Tried the car 6 hours later after work, it's 35  
> degrees out and symptom is the same.  Turns over, coughs and idles  
> for 15-20 seconds and dies.
>
> This one could be a doozy.
>
> -Matt, CO
> busted s4
>
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