Weird MC engine problem

[Bernard Littau]

Hi Phil,

> > Well, it must restart eventually.  How long does it behave like
> not wanting
> > to start?
>
> Variable - roughly two to five minutes.

That's a bit fast for a fuel problem like flooding.

> > When it will not start, does it have spark?  It might be a shorted coil,
> > that kind of sort of works until the cylinder pressure goes up,
> whereupon it
> > shorts due to the increased heat load on the coil.  After it
> cools, it works
> > again.  This is, of course, a real WAG!
>
> Spark is normal.

Hmm, still does not rule out a problem with spark under compression.

>
> > Have you swapped the ignition module for a known good one? (I'm
> assuming the
> > MAC-14 MC still has a separate ignition module, like the MAC-11 system)
>
> Yup - swapped the coil pack with another car.  Symptoms stayed
> with the car.

So much for the "short" (or "long") on the coil theory :-)

>
> I forgot to mention - on a significant number of th efailed start
> attempts, the engine kicks
> in and runs backwards for three or four revolutions.

Interesting.  Did you power wash the engine?  You may want to check the
distributor, especially the cap.  I've seen water or other foreign material
in the cap.  I've had these cars idle fine, but buck and stall under load or
increased rpms.  Foreign material can cause all sorts of crossfire events,
which might explain the backwards running, and the stall.

You're not off by one on the plugs, by chance?  Maybe swapped two leads?  I
suppose it might idle in such a state, though I have not tried this.

I'm reaching.  Normally, I'd come to you for advice :-)

Best,

Bernard Littau
Woodinville, WA
'88 5ktq