Hi, I've got a Pontiac 287 engine. The previous owner converted to electronic ignition. I'm trying to bench start the motor in the frame. I've confirmed I've got spark coming out of the 12v ignition coil. But no spark coming out of the plug wires from the distributor. I took the cap off and see that there is a burn mark on the exterior of the ignition module (see pic in link) - snipboard.io/dP4V8H.jpg. Does this mean my ignition module is fried? No good? Needs to be replaced? What could have caused this? Dave
Sounds like the cap and or rotor are not making connection. If the coil wire sparks when cranked the ignition is working. Spark not getting through or to the cap.
Certainly doesn’t look good. But if you have spark out of the coil, have you verified the rotor is actually rotating? I’m no expert in these matters, but would think if the module is bad, the coil wouldn’t fire.
The ignition coil is definitely sparking and strong. I know I have all of my plug wires correct. When I test any wire for spark there is none (used the old screw driver trick). I also set my timing manually at TDC and the rotor lined up with #1 on the cap. Not sure what else it could be.
Dave, remove the cap from the distributor and set it aside. Pull the coil wire out of the cap and leave the other end in the coil. Now hold the wire just above the metal contact at the rotor center and crank the engine. Use a good insulator to hold the wire so you don't get shocked. If the spark easily jumps to the rotor there may be a burn track right through the rotor to the distributor shaft. Look closely.
Pull distributor & with a few test leads You can bench test ( does not have to be in Engine ) With a Ground & a 12v source Car /Tool battery , & spin gear with fingers , Fast or one tooth @ Time ,, Coil, a plug ext , No mater a Hei, points Ext , Most time when a module goes bad it's bad but a few weeks ago I had one that was in the mentally Not work
I pulled off the cap to get a good look and noticed a burn mark on the electronic ignition module. Would this mean the module is no good?
If you have good spark at the coil, the module is good. That's the only job it has. Your problem is between the coil wire and the plugs. It could be a shorted rotor, carbon tracking in the cap or bad plug wires. It's not the module.
For a Joke Picking on a person , Take & draw a graphite line inside cap around to all the plug terminals
Weak spark due to module damage, just enough to see at coil tower and not visible elsewhere ? Try another module and check coil primary and secondary resistance for possible problem there and is match for petronix module.
From my own experience with Petronox, if the ignition switch is left on, it will burn out the module. If you use incorrect plug wires ( per Petronox, ) it can damage the module. The coil also must match their specs. If you have an oil filled coil and it’s mounted upside down, it will ruin the module, learned that one the hard way. Actually a new distributor is only slightly more expensive than a new complete distributor from them. Those modules are difficult to replace and you have to splice wires inside the distributor. I got a new distributor and replaced the coil and haven’t had an issue since Good luck with it !
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