Engine turning over but no spark

[Jbh09d]

So, I recently purchased a 1985 CJ7 . It ran fine for about a month and then it decided it didn't want to start. Engine is turning over but there is no spark at the plugs. I've replaced the ICM, coil, rotor button, distributer cap, wires, and plugs. None of this seemed to resolve the issue. The previous owner did foul up the wiring pretty bad under the dash but not sure if that would cause any of my issues. Only thing left I can think of is the distributor pickup coil. Any help would be greatly appreciated. Thanks.

 

[thundley57]

So, I recently purchased a 1985 CJ7 . It ran fine for about a month and then it decided it didn't want to start. Engine is turning over but there is no spark at the plugs. I've replaced the ICM, coil, rotor button, distributer cap, wires, and plugs. None of this seemed to resolve the issue. The previous owner did foul up the wiring pretty bad under the dash but not sure if that would cause any of my issues. Only thing left I can think of is the distributor pickup coil. Any help would be greatly appreciated. Thanks.

Definitely check the pickup coil which was the source of my similar problem. Resistance between the violet and orange spade connectors on the distributor harness (distributor side) should be 400-800 ohms which I discovered on this forum thanks to member Posi. Mine was reading 20 ohms, bought a brand new one which unbelievably was bad (0 ohms), exchanged it for another one (580 ohms) and I now have spark but am dealing with other issues as well.

 

[Posi]

With a fully charged battery (12.6) and good working meter probe the battery + side of the coil with key on (no start) other probe to battery - post.
Do the same test while cranking.
Post your findings.

 

[Torxhead]

This could be another bad coil connector cap.

 

[BowHunt3r]

My 79 CJ7 died last week. Same thing no spark. The HEI distributor coil pack was split open and melted on both ends. After rebuilding the distributor it still would not fire. Come to find out my aftermarket tach was bad. unplugged it at the distributor and the jeep fired right up. So far its running fine.

 

[Belizean]

My 79 CJ7 died last week. Same thing no spark. The HEI distributor coil pack was split open and melted on both ends. After rebuilding the distributor it still would not fire. Come to find out my aftermarket tach was bad. unplugged it at the distributor and the jeep fired right up. So far its running fine.

Curious how you figured out how it was the tach?