Elec woes, crank, no start after running then parked.

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MV8 said:
If "nfg" mean the tap test didn't work, pour water on the module next time it stalls and see if it comes back quicker. If it did work, next time see if the pickup is shorting when hot enough to the distributor body.

Loaded stumble (in gear, stall the converter) is typically weak ignition to the plugs but I thought it was only part throttle that this happens. Ohm the plug wires also.
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You have to be careful dumping water on a "real" module. The "fake" china modules, the transistor is fake. But on a "real" module, the transistor is insulated from the case, by the voltage on the coil NEG primary. When operating, this is above ground by the amount of the coil primary pulse, over a hundred volts. If there is dirt/ corrosion around the case, it will short and may not generate spark. Years ago I had that trouble, SB Mopar in my old Landcruiser. playing in snow/ mud/ water would cause it to miss badly I finally moved the coil and box up under the dash, and ran the coil wire out through a grommet in the firewall
 
Hey Steve,
FYI I put an SMP LX 101 pickup in my dizzy a few weeks back and the car would not run. My old one looked different than the new one. I had to put back the original. I have yet to ohm them out. Both had same part #.
 
I'm wondering if it's wiring or "incompatible" parts?
I'll go over it again.
Elec ign,
70+ charging system(square back alt, #3438150 Mopar voltage reg)
SMP coil # UC12 and another unknown name brand.
Tried both Mopar #4120505 and SMP LX101 ecu's
Mad bypass
Homemade replicated dash harness.
So obviously there are a few mods/changes I've done. All in hopes of reliability lol.
 
No, I checked coil volts after stalling. I think it was 6 ish on coil +ve and 1ish on coil -ve. That's after stalling and key in run.
Daves69 said:
Did you say you had a voltmeter attached to the Ign 1 side of the ballast when it starts to flutter, and voltage is not falling off?
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Alternator should really have no affect on ignition, unless it's not charging and the battery is "that dead," or it's charging full tilt and you would know that, hot, bubbling, smelly battery, lights very bright and maybe blowing out, etc.

I once had an overcharging problem between Vegas and San Diego, in the military. In the daytime, we drove for many many miles with the alternator intentionally disconnected. (Pulled the connector off the VR)
 
OK, so avoided this pos for a couple days, but figured I would reinforce the definition of insanity and keep doing same stuff and post test results.
BTW, I checked BH connectors and all good with die electric grease in there and no corrosion.
Load tested battery, good. I've been "watching" it as you could hear it "boiling" while charging approx 10 days ago. All tests have been good tho.

Car fired right up.
Tests while running
Batt voltage 14.24
Initial(va unhooked/plugged)18*
Idle rpm 825
Alt stud to block gnd 14.82V
Ballast resistor V 9.36/13.85
Coil +ve to block gnd 9.21V
Coil -ve " " 3.40V

Ran approx 10-15 minutes then died.

Tests below with me not touching anything after the stall. Key left in run.

Batt V 12.06V
Alt stud to block gnd 11.95V
Coil +ve 6.78 V
Coil -ve 11.8 V
BR 6.80/11.70
Tap test with dist lead...SLIGHT sound/spark from dist cap.
I also measured Coil res, Primary was O/L, but i beleive that's due to coil +ve and -ve wires hooked up??
2ndary 10.8K ohms(wire to cap unplugged obviously)
Tried to start, no spark(on #1 plug wire, OR on coil wire)
BUT, with timing light on coil wire, I would get a "flash/spark" every time I turned key to OFF and when I turned it to RUN???

I'll let it cool and fire up again.
I appreciate everyone's help and patience. Open to suggestions lol
 
Here's video Del, I'm off to bed(night shift), chk in later. But yes I swapped coil. Current one is a SMP #UC12. Not sure if they are designed to be vertical or horizontal??
67Dart273 said:
Tell me again have you replaced the coil?
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4spdragtop said:
Yes, swapped coil Del. I took another video I'm uploading right now.
Click to expand...
 
OOPS!! HERE IS A CLUE, Steve, post 63. You say after it stalled, Coil -ve 11.8 V

Coil NEG V should be LOW, the lower the better, with proper voltage on the coil+. Coil NEG should be no more than maybe 1-2V which key in "run", engine stopped, and with 6-9 or so on the coil +

THIS INDICATES that the coil is not drawing current through the box. ECU Box ground, intermittent coil, intermittent in coil NEG wire to box, or ECU connector terminal for coil NEG, or intermittent ECU OR ECU may be losing power, from it's box wire terminal, that wire goes over to "run" voltage.
 
Thanks for the chat and pointers Del. I'll try to get the tests over the next few days.
:thumbsup:
67Dart273 said:
OOPS!! HERE IS A CLUE, Steve, post 63. You say after it stalled, Coil -ve 11.8 V

Coil NEG V should be LOW, the lower the better, with proper voltage on the coil+. Coil NEG should be no more than maybe 1-2V which key in "run", engine stopped, and with 6-9 or so on the coil +

THIS INDICATES that the coil is not drawing current through the box. ECU Box ground, intermittent coil, intermittent in coil NEG wire to box, or ECU connector terminal for coil NEG, or intermittent ECU OR ECU may be losing power, from it's box wire terminal, that wire goes over to "run" voltage.
Click to expand...
 
Flipping thru elec notes I stumbled on this info I copied from SMP. The RU11 resistor I used is listed(orange highlights), it states to use with UC12X coil(I've tried UC12). Not sure what differences between the 2 are? It also states "WITHOUT STARTING BYPASS CIRCUIT" isn't that what the ballast resistor achieves?

20240727_045034.jpg
 
4spdragtop said:
Flipping thru elec notes I stumbled on this info I copied from SMP. The RU11 resistor I used is listed(orange highlights), it states to use with UC12X coil(I've tried UC12). Not sure what differences between the 2 are? It also states "WITHOUT STARTING BYPASS CIRCUIT" isn't that what the ballast resistor achieves?
Click to expand...
Not sure what they mean WITHOUT STARTING BYPASS CIRCUIT? The Ignition 2 circuit which bypasses ballast and sends full battery voltage to coil only comes into play when key turned to Start position? So why would that have anything to do with ballast why ballast is bypassed? And do some mopars, maybe older models, not have an Ignition 2 circuit?

It sounded like voltage to coil stayed consistent while it was running and until died so I don't think its a ballast resistor problem. And 9 volts + side of coil is right where it should be too....
 
I had a similar situation last year. Driving and car started bucking. I pulled over and the engine died. It turned over but wouldn't start. Fortunately, I carry all the necessary spare parts and basic tool kit. Checked; gas getting to carb . . . yes.
Spark . . . no.
BTW> if car starts but stops when key is released, the problem is ballast resistor.
Mine would turn over but wouldn't start at all.
Doing one thing at a time, I switched out the ECU. That wasn't it.
Replaced the coil . . . BINGO!
p.s. some coils require a ballast. My spare has one internal.
Later, I called product technical and asked whether I should disconnect my ballast.
Told, not necessary.
 
340sFastback said:
Not sure what they mean WITHOUT STARTING BYPASS CIRCUIT? The Ignition 2 circuit which bypasses ballast and sends full battery voltage to coil only comes into play when key turned to Start position? So why would that have anything to do with ballast why ballast is bypassed? And do some mopars, maybe older models, not have an Ignition 2 circuit?

It sounded like voltage to coil stayed consistent while it was running and until died so I don't think its a ballast resistor problem. And 9 volts + side of coil is right where it should be too....
Click to expand...
If anything it is the newer models which don' have the ign2 "on the key." They did however use that oddball what I call the "Jeep" starter relay. It has an extra contact that does that job.
So far's I've ever known, all 12V Mopars from the early days and up through what we "normally" discuss here, have the IGN2 contact on the ignition switch

Also, it would not be the first time that some catalog listing was AFU
 
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