I thought I'd follow up on this. I replaced the caps and did some
slight rework on that one poor resistor. One lead was *just* about to
fall off. The whole thing looks much better, but the van still
refuses to start. I didn't expect this to cure the no start problem
anyway. The leakage just didn't look severe enough yet to be causing
it. But it was definitely severe enough to require attention.

I'll keep digging and I guess I'll update this thread with the
findings.

Thomas Dorris

Your ECU may or may not be responsible for the no start. As usual, check for
spark and fuel pressure first. If memory serves, there will be spark, at
fixed timing, even if the ECU can't control ignition. If you have spark and
correct fuel pressure, it's time to check whether the injectors are firing.

Incidentally, with EEC-IV you don't need any scanners to read stored codes
or to perform on-demand diagnostics. You put the ECU in diag mode by
grounding the single pin connector. You read the codes with a test light
connected from B+ to the STO pin in the 6-pin diagnostic connector. Plenty
of information about the details all over the web.

Thanks, Happy. But this all started as a standard diagnostic
procedure. Checked for spark, got none so I started to track back to
components that might be involved. It came down to the TFI module and
the ECU. Since the ECU was easier to reach and I had an interest in
it anyway, it came out first. The TFI modfule is next. I just gotta
figure out how to get to that one bolt holding the distributor in
place so I can rotate it out before I can even attempt to get the
module off. I've never dealt with a distrubtor before, so this has
been a bit of a learning curve for me.

But the whole point of this thread was simply to discuss the potential
issue with the ECU. I was first curious whether others had seen this
and then I interested in making people aware of this potential on
these old, forgotten platforms.

Thomas Dorris

Just to finally update this thread. The problem was a malfunctioning
MFI relay (powers the ECU). But the problem wasn't just that the
relay stopped working. I wish it had because then the problem would
have been more obvious.

But nooo. The relay was working *just* enough to keep stuff powered
up, but then not actually function when you crank the engine. It had
just enough voltage drop that it really confused the ECU and
apparently just about everything else too, including me.

Oh well. Lesson learned. I enjoyed the exercise anyway. I wanted an
excuse to dig into this van a little deeper and that's what I got.

Thomas Dorris