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Intermittent start electronic ignition

Orange71SE

Orange71SE

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I have a random no start on a ‘71 440 charger that i converted to electronic ignition. Coil will have 12v with key in crank position but no output from the coil. I replaced the coil and the ignition module, still has the same issue. I have the “key run position” blue wire tapped into the blue/yellow wire for the ignition module on the same side of the ballast resistor. On the other side of the ballast is the 12v for coil and and brown wire for “key start position”. Is this set up correct?

C981799E-BE95-41E3-9010-A9DBDC9ED0B1.jpeg 7889812D-21CC-4B42-A195-D3C53185A2EC.jpeg
 
The factory electronic ignition needs good grounding, Block to Ignition module, and a good battery ground cable and connections.
Also check the reluctor air gap in the distributor, s/b 0.008"
 
451Mopar said:
The factory electronic ignition needs good grounding, Block to Ignition module, and a good battery ground cable and connections.
Also check the reluctor air gap in the distributor, s/b 0.008"
Click to expand...
Reluctor gap is at .008, has good ground, even made a jumper wire from battery neg to ignition module.
 
Best way to test is to separate the starter circuit from the ignition circuit and use another battery to power the ignition.

Just leave the key in the off position, then connect another battery with positive (+) to the ignition circuit at the ballast resistor, the ground (-) to the block.
Use a starter switch at the netural safety relay to crank the engine with the original battery.

If the car starts, the problem is in the wiring (maybe voltage drop or ground loop problem?) and not the ignition components.
If it does not start, the problem is either the ignition wiring or ignition components.
 
He said "Coil will have 12v with key in crank position but no output from the coil". Wouldn't that indicate that power is getting past the bulkhead connector? Sure sounds like a coil problem, though hard to believe a replacement was bad out of the box...................unless it came from AutoZone.
 
Ranger16 said:
He said "Coil will have 12v with key in crank position but no output from the coil". Wouldn't that indicate that power is getting past the bulkhead connector? Sure sounds like a coil problem, though hard to believe a replacement was bad out of the box...................unless it came from AutoZone.
Click to expand...
No, the issue im having is really random and when it does work the coil will produce a nice hot spark. Ive tried 2 different coils. Issue is present with both coils. I have checked the bulkhead connector countless times.
 
Well, you used the right tool... How is the alignment of the reluctor to the core of the coil? How are the bushings in the distributor? How's the fit between the advancer & the shaft?.....My suggestion... Close the gap down to .006.... With a DVOM read the signal from the pick-up coil, I seem to remember .8 volts while cranking is a good signal but it's been years.... Most folks just measure resistance through the coil & if it's good they assume the problem is elsewhere... But the module needs to see a voltage signal to trigger not the resistance... And if the magnet in the pick-up coil is weak of the gap is to large or the alignment of the reluctor/pickup is off you get a weak signal voltage...
 
Orange71SE said:
No, the issue im having is really random and when it does work the coil will produce a nice hot spark. Ive tried 2 different coils. Issue is present with both coils. I have checked the bulkhead connector countless times.
Click to expand...
.
How random? The issue I had was it would start when the engine was cold, but not start when the engine was hot. It was bad battery cables / connections in my case.
 
1 Wild R/T said:
Well, you used the right tool... How is the alignment of the reluctor to the core of the coil? How are the bushings in the distributor? How's the fit between the advancer & the shaft?.....My suggestion... Close the gap down to .006.... With a DVOM read the signal from the pick-up coil, I seem to remember .8 volts while cranking is a good signal but it's been years.... Most folks just measure resistance through the coil & if it's good they assume the problem is elsewhere... But the module needs to see a voltage signal to trigger not the resistance... And if the magnet in the pick-up coil is weak of the gap is to large or the alignment of the reluctor/pickup is off you get a weak signal voltage...
Click to expand...
Hmmm, ill try all of this tomorrow. Ill post likely pull all the components and wire them up and see if i cant test the whole system on a bench.
 
451Mopar said:
.
How random? The issue I had was it would start when the engine was cold, but not start when the engine was hot. It was bad battery cables / connections in my case.
Click to expand...
Real random, doesn’t seem to care if its hot or cold.
 
Can be the ick up coil going intermittent also. Easy check pull the distributor, use a voltage meter in AC and spinn the shaft should have a small MV signal generated out, that means it is sending the signal to the ecu.
 
Orange71SE said:
No, the issue im having is really random and when it does work the coil will produce a nice hot spark. Ive tried 2 different coils. Issue is present with both coils. I have checked the bulkhead connector countless times.
Click to expand...
I had a similar problem with the ballast bypass circuit. Car would only start when I released the key. Checked and double checked everything including the bulkhead connector and all looked good. As a last resort, I pulled the bulkhead connector and used a small screwdriver to just slightly bend the contacts on the suspected connector to make a more positive connection. Low and behold, she now starts as soon as I turn the key.
 
Thanks to everyone who gave input, so ultimately what i think happened was that the magnetic pickup in the distributor was budding up against the reluctor wheel even though i have checked the gap with a brass feeler gauge multiple times. The reluctor ended up getting damaged and so did the pickup. I ended up just sticking in a new distributor since the parts needing replacement were nearly as much a a new distributor.
 
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