Electronic ignition module trouble

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unicornhole

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Just finishing up a 340 swap. Had no spark. Replaced ignition module and it fired right up. Came back 20 minutes later and no spark again. Is there something that could be burning them up? Are they that cheaply made?
 
FBO.

5730E4EB-5B00-4E09-8908-46414E58E180.jpeg
 
Do some tests.

Measure coil POS and NEG voltage with key in "run." Coil + should be down quite a ways below battery, perhaps 6-10V. If it is "high" same as battery, then the box and or coil is not conducting, either bad connection, bad coil or bad box.

Coil NEG should be quite low perhaps 1 or 2 V. If it is quite high, 10-12V or so, the box is not pulling power through the coil.

If the coil is conducting, IE above voltages are OK, remove dist. connector. Take up engine harness side of connector, and tap the bare connector end against a ground, with a test gap rigged at the coil secondary. You should get one hot spark each time.
 
Gotta be grounded GOOD. I like an extra ground wire.
 
needs to be grounded
coil needs to be 8v coil with correct primary resistance paired with a ballast of correct resistance. these two added togther must limit current to 2-3 amps

regulator should be electronic rather than mechanical

AND
if you are running a big battery of capacity and cold cranking amps way higher than the original, it will maintain 12 volts and start the car perfectly well even when quite flat.

a Stall.
At pulling away RPM (1000-1500) with the alternator in Full-On Charge-mode, due to flat-ish but big battery.
You see your ammeter pretty much pegged to the end stop after starting the car. And then you stall it. cold weather, siezed brakes or snow bound wheels, tyre up against curb etc etc

The back EMF SPIKE from the coils in the alternator, when it stops abruptly, can take out the module...especially if the condenser is marginal or burnt out

even more likley if running a GM HEI 4 pin.

they can only put up with this once or twice

having bust two modules on two seperate visits and in the same manner i'm pretty convinced that this is a "thing"
Trying to drive my car backwards out of the same hole in the camping field at the track
i'm pretty convinced this plays a big part

on both occasions the car battery had been charging everything from phones E-cigs and blue tooth speakers the night before. Hung over, needing bacon and eggs and coffee, on a wet miserable morning, on a disused WWII airfiled in the middle of the UK, K frame resting on the mud, Yes i can stall it on an incline in long wet grass :)

i carry a spare

Dave
 
If you get the FBO module, you will get to bypass the ballast and buy a different coil.
It's made in America.
 
IDK if putting it in one of the hottest parts of the underhood, is gonna do it any good either...... not to mention not much airflow back there.
Electronics and heat don't fare well together.
 
I am not the electrician. BUT. Check your connections and grounds. I had a similar issue with my FBO. It ended up being the coil, which was a new epoxy Pertronics.
 
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