Are you ready for a real weird one? Random NO spark from a MP electronic ignition system despite numerous parts swapped around...

[CoronetDarter]

This is exactly what these cars are about, grabbing a buddy or sometimes more, hanging out, maybe something gets fixed (thankfully this time it did,) maybe not, buts it’s always a good time!

Not to mention, Greg's dogs missed me.

 

[Cheapsunglasses]

Not to mention, Greg's dogs missed me.

Dogs, hanging out, cars, fixing something? Great googly moogly!

 

[Kern Dog]

The HiRev7500 is planned to be my spare at trunk. But a friend on mine also got it and failed in a year or so.

I have a few months and 1200 miles on the one that just quit working. I had the matching ballast resistor in place too. No excuses.

Are we seeing a Page 10 yet???? C'mon man...I got money riding on that.

I would suggest a Rev-N-Nator unit Greg, but I think they are still backordered. You could try and contact them... The Rev-n-nator, the revinater, the revonator and R/T Garage - Mopar Restoration and Performance Services in Belle Plaine, MN

They work well up to 7,500 RPM. I have used several in different vehicles.

I did have one. It worked fine but the instructions stated that vacuum advance was not recommended. It got 2 mpg better with vacuum advance so I sold the unit years ago.

Yes on the Ignition Coil 1.5 OHM - I agree

So the Chinese Rick E Box shall now bee called

HIREV 6000

So Kern , what ignition coil brand and OHM rating is your coil

Your Ballast Resistor , what OHM rating is your ballast

When I first started this thread, I took a reading of the coil but I don't remember the number. It is an Accel yellow and It was within the range that Ehrenberg stated in the instructions:

The ballast in the kit was this one:

I expected the resistance to be .55 but I thought that I got a 1.6 number. I'll have to go out and recheck that.

 

[Kern Dog]

Here we go...
This is the ballast resistor that was with the distributor and ECM.

Ready to test.

The resistance with the probes touching...

Now the resistance with the probes on the BR.

It is dead. It reads the same as when the probes are not even touching each other.

 

[CoronetDarter]

That R55 BR just seemed cheaply made.

 

[Nacho-RT74]

The HiRev7500 I got it came without instructions but it was just the ECU, not the rest. I can’t recall which ballast and coil was running at the time ( maybe 13 years ago) but pretty sure it was both MSD. Dunno my friend thought. I just used it maybe couple of weeks while I was waiting for the Rev-N-Nator to be delivered.

 

[MWbirdLOVER70]

I have the FBO advance limiter plate but that is all I have from them.



I did not feel the battery cable. The battery is in the trunk and the main cable from the starter to the trunk mounted solenoid is only live when I am cranking it over. At the starter end, it is clear of the headers.

Again, thank you to all that took the time to chime in. The car is back up and running and what went wrong is a bit disappointing to me.
Two parts failed at the same time though I don’t know how or why. Both the ballast resistor and ECM crapped out. I had some help today….

View attachment 1701576

Rich, AKA CoronetDarter came over in the Coronet. He brought tools and was a welcome help. He has a form of electronic ignition so we used the Coronet as a test mule along with two other cars here and a truck. We tested voltage at the coil and ballast on the Coronet, my 72 Duster:

View attachment 1701578

A 75 Power Wagon:

View attachment 1701579

Of course, Jigsaw…

View attachment 1701580

Every vehicle had a different number. The Coronet and “Ginger” the red car had the highest readings, near 11 volts with the engines off. The other cars varied between 7-9 volts yet they all run fine. Checking the other cars was intended to reveal a weakness in the red car since it wouldn’t start. Instead it confused me because that low of a voltage reading should not start and run.
Yesterday on the roadside, the car was untouched and not starting so my diagnostic list was 1) Check for fuel, 2) Wiggle wires looking for loose connections 3)Replace ballast resistor. Each thing I did was followed by trying to start it.
At home I figured the ballast resistor was fine since changing it made no difference so I put it back in. I charged the battery. This morning I put in a different ECM and still no spark. Rich noticed that the plastic connector to the ballast didn’t click on with a snug fit. He thought maybe it could be partially to blame. The terminals on the BR wiggled a little, I don’t know if that matters. I think It is a ballast that came with an MSD coil, I don’t recall. All the times I’ve had random no spark issues, I’ve swapped around parts. I don’t remember where all the stuff came from.
I replaced the ballast resistor with a spare from the shed and BOOM, it starts and runs!
View attachment 1701588

That is a generic parts store ECM that is supposedly rated to about 5000 rpms. It is fine for now. At this point, I knew the ballast resistor was bad but To confirm things, I tried the blue ECM I was using along with an MP Chrome box.

View attachment 1701590

View attachment 1701591

I tried the blue and chrome boxes in the Duster and neither one worked in that car either.
Yes, I threw them out. I have made the mistake of putting junk electronic parts back in the shed only to be pissed later when they don’t work.

Ballast a def weird one. I’m used to them having the starts and then does after you let off after starting” scenario but this year it was on cranking and went through all the usual steps and swapped ballast and bingo. Looks like we both members of the ballast club this year. Glad to hear she’s better

 

[Kern Dog]

It happened again today.
The last time it lost spark, I had to tow it home. This time, I was at home. I can be thankful for that.
Again, this problem is intermittent. It is random. It can start fine for months, then without touching anything under hood, it won’t fire.
OR I go to restart it after it has ran a bit and it gets no spark.
This is the only car that acts this way. I have three cars and a truck with the Mopar electronic ignition. The truck does occasionally puke a ballast resistor but otherwise, it is reliable. Jigsaw always starts and it has a new Evans harness like I have in Ginger. The two cars are almost identical in ignition systems.
I don’t know if I am getting any closer to figuring out the problem despite lots of great advice from forum members.
I bought this guide from HalifaxHops:

I got no spark to the plugs and no spark from the coil. As I’m cranking, the starter spins slower and slower. Battery voltage was at 12.04. I put a charging unit on it to bring it back up. I can’t test for voltage to each component (and get any accurate info) until the battery has adequate charge. It will crank but not consistently fire. It did start and run but wouldn’t start again a few minutes later.
The car does sit awhile between uses and I don’t check battery voltage before I go to drive it. The time I had to tow it home, the battery faded fast as I tried to get it restarted on the side of the road. The battery charge may have been low that day too. I’m now wondering if by driving it with a low charge if somehow it damaged the ECM. Before the last incident, I had the Ehrenberg Hi Rev unit in place and the matching ballast resistor.

This time after testing it I spritzed it with brown paint to remind me that it is crap.

This chrome one was on the car awhile back when I lost spark so I marked it too.

I tested the ECM from Ginger on the other car, Jigsaw.

It started right up. In fact, I tried a couple of ECMs that I thought were bad and they worked too.
I’m curious if the ECMs are sensitive to low battery voltage. Is it possible to have enough charge to spin the starter but not enough to energize the ignition?
Can the alternator that is working to restore charge to the battery be responsible for killing the ECMs?
I’m grasping at straws here. This problem persists. If the other cars were unreliable, I’d just give in and switch to an MSD or Pertronix for this one.

 

[HEMIB]

Found when my battery voltage goes to around 10.5 cranking i lose spark put a jumper battery on it or charge & it start's right up found it happen,s mainly when hot Orange Mopar ECU,
With my 340 point's car it will start as long as the starter turns the engine .

 

[Cranky]

It happened again today.
The last time it lost spark, I had to tow it home. This time, I was at home. I can be thankful for that.
Again, this problem is intermittent. It is random. It can start fine for months, then without touching anything under hood, it won’t fire.
OR I go to restart it after it has ran a bit and it gets no spark.
This is the only car that acts this way. I have three cars and a truck with the Mopar electronic ignition. The truck does occasionally puke a ballast resistor but otherwise, it is reliable. Jigsaw always starts and it has a new Evans harness like I have in Ginger. The two cars are almost identical in ignition systems.
I don’t know if I am getting any closer to figuring out the problem despite lots of great advice from forum members.
I bought this guide from HalifaxHops:

View attachment 1751936

I got no spark to the plugs and no spark from the coil. As I’m cranking, the starter spins slower and slower. Battery voltage was at 12.04. I put a charging unit on it to bring it back up. I can’t test for voltage to each component (and get any accurate info) until the battery has adequate charge. It will crank but not consistently fire. It did start and run but wouldn’t start again a few minutes later.
The car does sit awhile between uses and I don’t check battery voltage before I go to drive it. The time I had to tow it home, the battery faded fast as I tried to get it restarted on the side of the road. The battery charge may have been low that day too. I’m now wondering if by driving it with a low charge if somehow it damaged the ECM. Before the last incident, I had the Ehrenberg Hi Rev unit in place and the matching ballast resistor.

View attachment 1751940

This time after testing it I spritzed it with brown paint to remind me that it is crap.


View attachment 1751941

This chrome one was on the car awhile back when I lost spark so I marked it too.

View attachment 1751942

I tested the ECM from Ginger on the other car, Jigsaw.

View attachment 1751937

It started right up. In fact, I tried a couple of ECMs that I thought were bad and they worked too.
I’m curious if the ECMs are sensitive to low battery voltage. Is it possible to have enough charge to spin the starter but not enough to energize the ignition?
Can the alternator that is working to restore charge to the battery be responsible for killing the ECMs?
I’m grasping at straws here. This problem persists. If the other cars were unreliable, I’d just give in and switch to an MSD or Pertronix for this one.

MSD's are picky about battery voltage too.....

Found when my battery voltage goes to around 10.5 cranking i lose spark put a jumper battery on it or charge & it start's right up found it happen,s mainly when hot Orange Mopar ECU,
With my 340 point's car it will start as long as the starter turns the engine .

Yup....my race car had electronic ignition but my old drivers were points.

 

[DeltaV]

Gremlins

1) Check the contacts on the harness connector:
- Check for pushed or loose contact(s)
- Check for bad/failing wire termination at the contact.
- Check for corrosion on contacts and wire.

2) Similarly, check the other end of harness too.

3) Take the harness out of the car and ring-out the wiring while one person gently manipulates the harness near the connectors and along the length of the harness. Basically, you're searching for an intermittent open. An internal wire-to-wire short will be more difficult to check, but doable.

 

[RJRENTON]

It happened again today.
The last time it lost spark, I had to tow it home. This time, I was at home. I can be thankful for that.
Again, this problem is intermittent. It is random. It can start fine for months, then without touching anything under hood, it won’t fire.
OR I go to restart it after it has ran a bit and it gets no spark.
This is the only car that acts this way. I have three cars and a truck with the Mopar electronic ignition. The truck does occasionally puke a ballast resistor but otherwise, it is reliable. Jigsaw always starts and it has a new Evans harness like I have in Ginger. The two cars are almost identical in ignition systems.
I don’t know if I am getting any closer to figuring out the problem despite lots of great advice from forum members.
I bought this guide from HalifaxHops:

View attachment 1751936

I got no spark to the plugs and no spark from the coil. As I’m cranking, the starter spins slower and slower. Battery voltage was at 12.04. I put a charging unit on it to bring it back up. I can’t test for voltage to each component (and get any accurate info) until the battery has adequate charge. It will crank but not consistently fire. It did start and run but wouldn’t start again a few minutes later.
The car does sit awhile between uses and I don’t check battery voltage before I go to drive it. The time I had to tow it home, the battery faded fast as I tried to get it restarted on the side of the road. The battery charge may have been low that day too. I’m now wondering if by driving it with a low charge if somehow it damaged the ECM. Before the last incident, I had the Ehrenberg Hi Rev unit in place and the matching ballast resistor.

View attachment 1751940

This time after testing it I spritzed it with brown paint to remind me that it is crap.


View attachment 1751941

This chrome one was on the car awhile back when I lost spark so I marked it too.

View attachment 1751942

I tested the ECM from Ginger on the other car, Jigsaw.

View attachment 1751937

It started right up. In fact, I tried a couple of ECMs that I thought were bad and they worked too.
I’m curious if the ECMs are sensitive to low battery voltage. Is it possible to have enough charge to spin the starter but not enough to energize the ignition?
Can the alternator that is working to restore charge to the battery be responsible for killing the ECMs?
I’m grasping at straws here. This problem persists. If the other cars were unreliable, I’d just give in and switch to an MSD or Pertronix for this one.

WHY are you saving the defective/defunct ECU's......it's just like saving burned out light bulbs or blown fuses or to be crude..,like used condoms.....makes no sense.....throw them away.....
BOB RENTON

 

[Kern Dog]

I did notice this…
Here is a new harness for a conversion:

The contacts all look pretty, huh?
Now look at the one in the car.

The terminals are grungy but are they bad enough to be an issue?

I tried two different spare coils and still no spark.
The testing methods of the booklet are not enough!

 

[DeltaV]

WHY are you saving the defective/defunct ECU's......it's just like saving burned out light bulbs or blown fuses or to be crude..,like used condoms.....makes no sense.....throw them away.....
BOB RENTON

Maybe they really aren't bad units!

 

[MWbirdLOVER70]

I did notice this…
Here is a new harness for a conversion:

View attachment 1751984

View attachment 1751985

The contacts all look pretty, huh?
Now look at the one in the car.
View attachment 1751987

View attachment 1751988

The terminals are grungy but are they bad enough to be an issue?

I tried two different spare coils and still no spark.
The testing methods of the booklet are not enough!

Maybe try cleaning those grungy contacts and so dielectric grease?

 

[Kern Dog]

WHY are you saving the defective/defunct ECU's......it's just like saving burned out light bulbs or blown fuses or to be crude..,like used condoms.....makes no sense.....throw them away.....
BOB RENTON

What is your address? I’ll send all the bad ones to you.
The reason that I saved them was validated today. Two of the four that provided no spark in the red car actually worked in the other car.

Maybe they really aren't bad units!

The booklet stated that by testing voltage at the ECM plug, the number needs to be within one volt of the battery. Both cars show more than 1.5 volts difference despite one car starting and the other not. I might clean the terminals in the plug and try tomorrow. If nothing else, I could wire in the new harness.

 

[turbine68rt]

Points. Problem solved.
40k miles and never left me stranded.

 

[Demonic]

Autopsy that blue box - see what's under that transistor cover?

 

[BeepBeepRR]

Autopsy that blue box - see what's under that transistor cover?

Goo and electronics... Probably popped a capacitor.

 

[HEMIB]

Did it have a screw in it to hold it onto the terminals it not the rubber shroud maybe pushing it back not allowing the terminals to make good contact ,I notice some of the new ones havent got a provision for the screw