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Electronic ignition troubleshooting help

Bob I wish you were closer. I am sure both of us would as they sat NERD OUT! I just got a rarer Race ECU in and all the potting is pretty much leaked out. I knew this when I bought it. Dam thing tested good! Kind of thought so. Going to test the crap out of it and possibly re pot it.
 
Bee1971 said:
Trying to find Made In The USA New Old Stock ECUs

Mopar Performance ECUs from the 80s and 90s at swap meets or online

I found this brand new on EBay this past winter for $35.00 View attachment 1068150
Click to expand...

Very good find....the old MP and NOS stuff is getting harder and harder to find. Would be great if you find an old MOPAR module tester (Hallifaxhops??) to test your modules. In all my years of Mopar vehicles, I've always used points/condenser, with one exception....my WP23U1A****** Charger 500.....which l used the Mopar Performance kit......which failed and left me along the road. My RS23VOA****** is an origional numbers match car and use a Prestolite dual point distributor (recurved), which I can buzz up to 6000 RPM. For a occasional use car l like the old way..... just my opinion of course.
BOB RENTON
 
LOL I actually have sold a few of them in the past. I have a zetron with all the cables only issue is the case fell and is cracked up pretty much. Works great and has all the cables. Mopar, Ford, GM and AMC also I believe. No book though. I would part with that one since I have another one. Dual points are great if they are working properly and have good points and cond in them. I have tested them to 8K no issues at all.
 
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HALIFAXHOPS said:
Bob I wish you were closer. I am sure both of us would as they sat NERD OUT! I just got a rarer Race ECU in and all the potting is pretty much leaked out. I knew this when I bought it. Dam thing tested good! Kind of thought so. Going to test the crap out of it and possibly re pot it.
Click to expand...

YES.....so do l....one nerd to another.... If the race ECU tests good...great if not, is it possible to remove all the potting compound and identify the board mounted components and PC board foil patterns, enough to make a schematic diagram of the circuit to better analyze the design and functionality, perhaps to duplicate and improve the design or determine the how and why of the failure, if that was what occurred. Let us know how you make out...
BOB RENTON
 
It is good let me see how it cleans up. Dam sand is like concrete and I dont want to break the board. No idea what it was mixed with definitely not potting. That's all over whats left of the box.
 
Update.

Installed the new ECU from Mancini. I even ran a ground wire from the mounting bolt to the engine block. Charged up the battery and checked for spark. Same as before. The spark is strong and regular, but yellow. Repeated the test with a jumper wire to Coil +. Same results. So with little confidence, I went ahead and tried to start it. Of course it didn't start. Cranking voltage is the same, 8.5v. With the ECU disconnected it's 10.5. Same as before. In fact, this isn't much of an update because not a dam thing has changed.

Double checked the air gap. It is perfect at .008. I previously posted all the wiring resistance values which no one commented on so I assume they are normal. The distributor was rebuilt (not by me) so I guess I should have faith that it was done correctly. What else could be going on? I know the cranking voltage is a little low, but with the ECU disconnected it rises to a more acceptable level (10.5v) which to me says the problem is probably not in the ignition switch or bulkhead wiring. Besides, even when running 12v straight to the coil I still get that yellow spark and a no-start condition. Have I been unlucky enough to have purchased 3 non-working ECUs and/or 2 non-working coils?
 
At this point I would button everything up, all wires connected properly, distibutor cap on, etc. Pull a few plugs, reattach the plug wires and ground the plugs. Crank and note if they spark. If the plugs spark that tells everything to that point is working, might not be optimal but should be enough to start it. If you have spark at the plugs its either a timing or a fuel issue. I still think your 180 out. Just my opinion.
 
IF you are using suppression core wires (resistor core wires) and in conjunction with resistor plugs, the spark will appear as a "yellow-ish" appearing spark. This is normal.
Reiterating the point: are you sure the distributor is correctly oriented with respect to the firing order and the TDC mark on the vibration damper? It may be time to check (double and triple check) again......just to be sure.
One additional consideration may be the POSITION of the distributor's RELUCTOR wheel in relation to the position of the distributor's ROTOR. IF not in correct orientation, the spark may be occuring after the rotors tip has passed the caps wire terminal.......just a thought....
BOB RENTON
 
RJRENTON said:
IF you are using suppression core wires (resistor core wires) and in conjunction with resistor plugs, the spark will appear as a "yellow-ish" appearing spark. This is normal.
Reiterating the point: are you sure the distributor is correctly oriented with respect to the firing order and the TDC mark on the vibration damper? It may be time to check (double and triple check) again......just to be sure.
One additional consideration may be the POSITION of the distributor's RELUCTOR wheel in relation to the position of the distributor's ROTOR. IF not in correct orientation, the spark may be occuring after the rotors tip has passed the caps wire terminal.......just a thought....
BOB RENTON
Click to expand...

So a yellow spark is OK? I was chasing another phantom.

See my previous post regarding the distributor. I am 100% positive it is installed correctly. Again, the car started and ran fine with the current installation. Do distributors jump out of time on their own?
 
The car doesnt run, take nothing for granted. Correct distributor orientation is an easy check.
 
What is the pickup coil resistance supposed to be, as measured through the 2-wire connector?
 
I just saw this thread. Another guy in AZ who can’t get his engine started. And you’ve been trying to get yours started for about six weeks now. Mine started up first try and I drove it two weeks ago. One week ago no start. Still the same today. I have spark at my coil wire but not at the plugs..
 
OK I will just throw some simple stuff in the mixer as food for thought. Dealing with a stock mopar ignition system can be challenging.
Question for the OP here, have you verified that you have full battery voltage to the ignition when you are cranking the engine with the ignition key??
There are 2 feeds from the ignition switch and one pulls down voltage from the accessory through the fuse box like when radio loses power momentarily when starting the car. The other feeds full voltage to power the ignition. This is a well known problem with these cars intermittently losing the ignition side.

If I am posting something already stated I apologize. I have only sparsely followed this thread.
:luvplace: :popcorn: :BangHead:
 
Curt Chambers said:
What is the pickup coil resistance supposed to be, as measured through the 2-wire connector?
Click to expand...
150 Ohms or more resistance - 150/900 Ohms

Make sure the reluctor on all eight points is either not touching the pickup coil or the gap gets to large as the distributor spins
Worn out distributor bushings or the pickup plate itself

.008 Air Gap
 
64fury74charger said:
Question for the OP here, have you verified that you have full battery voltage to the ignition when you are cranking the engine with the ignition key??
Click to expand...

Yes. Cranking voltage to the Coil + is 8.5v, which I realize is low. However, I've tried a jumper wire giving 12v directly to the coil and it made no difference. I also cranked the engine with the ECU disconnected and got 10.5v at the coil. That could suggest a problem in the ECU-distributor circuit. But it also means I have a 2v drop through the ignition switch and bulkhead connector. That's too much and will have to be addressed also, even if it is not the main culprit here.

My suspicions are now falling on the distributor. The pickup coil resistance is 850 ohms which, depending on the website you consult, is either too high or at the high end of normal. Since everyone has been telling me to remove the distributor to make sure its installed correctly I'll probably be checking this out further. I also noticed that the harness connector from the distributor to the ECU harness does not snap in all the way. But it seems to be making a good connection nevertheless, since the resistance reading is the same going through the pins in the ECU plug.
 
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