GM 8-pin hei weak spark

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bbab3

bbab3

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I just finally finished installing a 8-pin Accel GM hei and am having an issue with a weak spark. I have checked for a good ground the module and the motor, and the module has 12V supplied to it. The C terminal is connected to negative side of a MSD 8207 coil and the tach. Maybe defective module? Thanks
 
You for sure have a good heat sink and have not overheated the module? Monitor 12V while spinning a distributor to trigger it. They do not normally (at least GM) draw coil current unless triggered. Maybe the load is pulling down the voltage on the supply wire. "Usually" if something as these triggers at all, it's "good."

Did it ever work right? Maybe the coil is simply not compatible. Try a different coil. With a GM 4 pin and no ballast, even my old original Mopar coil gave a MUCH more impressive spark.
 
Why are you using a 8 pin module that reqd specific inputs on GM cars?
 
We have a FE Ford on the run stand with a HEI. Weak spark also. tried coil and module. No help. Ordered a new distributor it just came. I'll let you know once he installs it. He got the same distributor.
 
Not sure about he 8 pin but Accell has a bad track record wit the 4 pin modules. Have a friend that dirt tracks with one and he brought 5 over to be tested and all failed, gave him a NORS Kem one two years ago and he still uses it.
 
I am going to start testing cranking voltage and the coil resistance. then pull the distributor and check the pick up. All parts are new, which doesn't means much these days. Went with the 8-pin after reading #Trailbeast posts. A major pain in the *** when starting motor for the first time.
 
halifaxhops said:
Not sure about he 8 pin but Accell has a bad track record wit the 4 pin modules. Have a friend that dirt tracks with one and he brought 5 over to be tested and all failed, gave him a NORS Kem one two years ago and he still uses it.
Click to expand...
I pull every GM 4 pin 990 module out of the wrecking yard I find. Have one in My Chevy HEI going on 30 some years.
 
Looks to be the coil. .3 ohms primary and 1,823 ohms secondary. According to MSD specs needs to be .355 ohms primary and 4.4K ohms secondary. And now to call MSD about quality control.
 
No, a MSD 8207 solid state blaster coil
 
I have used many 8207 coils, including the latest ones made in China, never had a problem. Suitable for HEI. Measuring sec coil res with a DVM can give unreliable readings.
 
You have ANY other coil(s) you can try? May very well be that is it
 
I only have one coil. I going see if my neighbor has a spare just to double check.
 
Problem solved. It was the coil. Another great product made in China!
 
With the 8-pin GM HEI module, best and easiest to use the GM e-core coil which goes with it since you just grab the GM cable which connects the two. Magnum engines have a similar-looking e-core coil, but would have to fab your own custom cable, if that interested in staying more-Mopar. Re "why the 8-pin?". Because it is best, using sealed weatherpack connectors and easy coil connection (above). Only other thing needed is 12 VDC to the coil and ground. The white wire from GM coil is for a tach signal (optional). You don't need to use the other module connector, but can for spark control from an engine controller like Holley Commander 950 which offers a special cable for that. Best to run a dedicated ground wire from the HEI module mounting screw, and ditto for the Mopar ECU and Vreg. More grounds is always good.
 
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