gm hei no spark?

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joshua dewitt

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I was havn trouble with chrysler 4 pin box. So i did the gm hei module conversion. 4 pin on heat sink. Grounded. Wired correctly to every post found. New blaster 2 coil. And still no spark to distributor. I verifed 4 pin. Positive accross and according to inyernet is good. Tried a second one. Same thing. Verifed wires again. No spark. Have 12v ignition. At coil and hei module. Is a new procomp distributor. Was working with 4 pin but all was real weak.... Possible pickup in distributor? Multimeter on ac shows a various signal. Appears ok? What is gospel on pickup with meyer readings? Ohms? Etc... It beeps with continuity? Im baffled.... Any help here would. Be appreciated.
 
Module body well grounded either through the screw holes or the backing aluminum.
12v at the coil pos and module pos both.
No idea what the ohms on the procomp is, but a 1v or so DC signal is needed.

Wired like this.

4Pin.jpg
 
Module body well grounded either through the screw holes or the backing aluminum.
12v at the coil pos and module pos both.
No idea what the ohms on the procomp is, but a 1v or so DC signal is needed.

Wired like this.

View attachment 1715082093
That is exactly how it is wired. I even ran a groynd wire from heat sink block to ground stud. Just tried another coil this one epoxy flame thrower 1.5 ohm. And still no spark.
 
That is exactly how it is wired. I even ran a groynd wire from heat sink block to ground stud. Just tried another coil this one epoxy flame thrower 1.5 ohm. And still no spark.
Even verifed 12v positive at coil and b terminal at hei module. And verifed 12v negative on ground on heat sink... Im baffled....
 
Even verifed 12v positive at coil and b terminal at hei module. And verifed 12v negative on ground on heat sink... Im baffled....

Then if you have a good module (you said you tried another one) it has to be an issue with the distributor. (It is a magnetic pickup distributor right?)
Got a stock electronic distributor laying around? :D
It doesn't have to be installed or anything, just connected to the module and turned by hand works fine for testing for spark.

Also tighten up on the module to heatsink hardware if you can.
I have seen those aluminum screw sleeves not contact the backing plate of the module and not ground even with screws in them.
 
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Then if you have a good module (you said you tried another one) it has to be an issue with the distributor.
Got a stock electronic distributor laying around? :D
It doesn't have to be installed or anything, just connected to the module and turned by hand works fine.
Tjat is what im thinkg
 
POST A LINK TO YOUR distributor.........Some of those already have a module IN THE distributor

ProComp.jpg
 
Of course. The pickup unit is what triggers the module to "make spark." You have "any other" magnetic distributor you can "alligator clip" in to test?

Does that Pro Comp thing have a pickup coil adjustment similar to the Mopars?

Also you said 'was working with Mopar 4 pin but weak spark'

The pickup WILL NOT cause a weak spark, but it could trigger intermittently, causing a miss or a "once in awhile" spark

What do you have for supply voltage?

How did you ground the HEI? Photo?
 
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Would a bad pickup coil cause no spark from coil wire to distributor? Pulled coil wire and near ground. Crank... No sparky arcy?
Of course, as there is nothing telling the module to fire without a working magnetic pickup coil and a vane going by it to create the field that makes the volt or so that the module needs to see to break the ground to the coil causing it's field to collapse and generate the spark.:D
 
Then if you have a good module (you said you tried another one) it has to be an issue with the distributor. (It is a magnetic pickup distributor right?)
Got a stock electronic distributor laying around? :D
It doesn't have to be installed or anything, just connected to the module and turned by hand works fine for testing for spark.

Also tighten up on the module to heatsink hardware if you can.
I have seen those aluminum screw sleeves not contact the backing plate of the module and not ground even with screws in them.
it has 12v negative with meter on the rivet hole on the module, that should and appear to be properly grounded , correct?
 
it has 12v negative with meter on the rivet hole on the module, that should and appear to be properly grounded , correct?


DETAIL how you are measuring this....... You have the other probe "where?"

With battery voltage jumpered to the coil+ and module +..........

With one probe of the meter on the HEI screw hole.......

With the other probe on ground.......

YOU SHOULD READ ZERO

With the other probe on "battery" you will read 12V and neg or pos depending on which probe where IE pos probe on battery, neg probe on HEI screw hole, should read +12 or "just 12" depending on meter
 
A PHUCKING PHOTO COULD GO ABOUT A THOUSAND MILES towards "seeing" what you have here
 
it has 12v negative with meter on the rivet hole on the module, that should and appear to be properly grounded , correct?

Continuity from the negative terminal of the module to the mounting hardware and heat sink , not volts positive or negative.

Del :D
 
Of course. The pickup unit is what triggers the module to "make spark." You have "any other" magnetic distributor you can "alligator clip" in to test?

Does that Pro Comp thing have a pickup coil adjustment similar to the Mopars?

Also you said 'was working with Mopar 4 pin but weak spark'

The pickup WILL NOT cause a weak spark, but it could trigger intermittently, causing a miss or a "once in awhile" spark

What do you have for supply voltage?

How did you ground the HEI? Photo?
looks identical to the mopar stock distributor.... just a new unit by procomp with a mild curve in it. bought from summit, I did get it to run briefly with the 4 pin unit, but hasn't worked well at all lately, gave up on 4 pin. might have been the dizzy I guess...
I do have a stock unit, just worn out .. just plug in and spin it? should make coil spark on and off if center wire near grounded to see a spark of distributor?
 
Continuity from the negative terminal of the module to the mounting hardware and heat sink , not volts positive or negative.

Del :D
well ok yes continuity... I revered the leads used a 12v positive dvom reading, and used grounding rivet and heat sink block and shows a reading...
 
I had a very similar issue when I did the conversion myself. I used a brand new accel dizzy. looks like the reluctor gap is what you may need to adjust.i did it with mine and it was wayyyyy off.adjusted the gap and car has been running perfectly ever since.
 
Ok. Summit is sending me a new one . i do enough business. No problems there. ..... It is a pro form 66990... No spark from coul wire in block cranking with cap on. I removed distributor. And spun by hand with kry on with new gm hei set up. Shot one hell of a spark... Spinning fast good.... Went slow seamed spuratic? When pushing up on distributor shaft ad in car slowly seamed like hit and miss... Put in old mopar unit. And spun fast sparks good. Better pushed up slowly spining too. Possible distributor grounding out when installed in block? Something i friend possibly suggested. ... Any one seen this. Type of issue?
 
Ok. Summit is sending me a new one . i do enough business. No problems there. ..... It is a pro form 66990... No spark from coul wire in block cranking with cap on. I removed distributor. And spun by hand with kry on with new gm hei set up. Shot one hell of a spark... Spinning fast good.... Went slow seamed spuratic? When pushing up on distributor shaft ad in car slowly seamed like hit and miss... Put in old mopar unit. And spun fast sparks good. Better pushed up slowly spining too. Possible distributor grounding out when installed in block? Something i friend possibly suggested. ... Any one seen this. Type of issue?

Please re-word this and be more specific. There should not be enough "push up" play if that is what you are getting at........that would make any difference. You might try driving it with a drill......not for speed, but to establish a steady RPM, and see if the spark "seems" more rhythmic
 
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