[s-cars] Missing once more

[Marc Swanson]

> could it be what seems like a more commonly appearing problem for 
> several listers- fuel flow/pressure? 


Along those same lines, your symptoms mirror something I helped diagnose
on Brian Weldon's 93 S4 w/MRC chipset.  His car started running rough
and all of the usual ignition component suspects checked out fine.

I hooked up my zietronix wideband o2 meter and discovered that he was
running lean when the miss (detonation) occurred.  I measured the
voltage at the fuel pump and sure enough it was a full volt less than on
my car.  As an experiment I jumpered direct 12v to the fuel pump and
when we went for another test run the miss was completely gone.

The culprit ended up being the alternator, which was only producing
about 13.5v at the battery with the engine running.  He replaced the
alternator and all is well.

So anyway, if you have access to a wideband sensor my first step would
be to see if your problem is fuel related or ignition related by closely
monitoring the A/F.


-- 
-Marc Swanson-
95.5 //S6 Avant
87 4ktq
www.mswanson.com/audi