Finally solved the no start problem!!!

So-- it would crank, but no fire. I took all of the advice I found on the forum, first suspected the digiplex boxes (after having confirmed there was fuel delivery), and so I took them off, cleaned all the ground points and ran dedicated ground wires to a lug welded to the chassis.

I eliminated the original quick-disconnect battery switch, and replaced it with a new and robust unit I had laying around from my racing days.

Verified 12.9 volts at the battery terminals.

I even ran a dedicated ground from the Fuel Injection box on the right side of the trunk.

Still -- no fire. But it cranked away just fine, and pulling the safety switch on the Fuel Distribution body-- did make the frequency valve buzz and the fuel pump whine.

Then it dawned on me that just because the motor cranked over with the ignition key --- didn't mean it was also completing the circuit to the ignition system. So-- I pulled the columns plastic off, and went through the PITA to remove the tumbler, switch, and steering column lock hardware. I sprayed some Contact Cleaner in the electrical parts as good as I could--- worked the switch by hand a few dozen times between spraying, and then persuaded it all back into the casting.

And Voila!!--- it fired right away and runs better than ever. I suppose the other stuff I did trying to fix it was needed anyway. I repeated the restart 6 more times over an hour to make sure-- but it appears I've fixed it!

One question, though. When I had the Digiplex boxes on the bench I tested them with a vacuum pump. One held vacuum with no problem. The other would leak down after about 4 seconds (with 15 inches applied to it). Anyone know whether there is a way to replace just that component?

I'm concerned that the current situation means I may not be getting full advance on one cylinder bank. And-- of course, having a slight vacuum leak on top of it. Not sure if that would adversely affect other engine performance

Any comments appreciated.

Michael
NorCal -- East Bay

 

Steve,

Thanks for posting the interior pics. I was always curious what the bugger looked like inside. As someone else posted on another thread, I can see that the conformal coating they lathered on would make servicing this unit a major pain.

I'll contact that Outfit about the component:

http://www.ecudoctors.com/

I suppose the best way to confirm whether that one failing unit is having a real effect on the advance curve is to try a timing light on both banks and bring the engine speed up.

Thanks again,

Michael