I have an issue with my ignition system. I recently encountered a problem where the engine runs rough and sputters and chugs on acceleration and misses at speed. While it was at the mechanics he was poking around with his voltage tester and found that when he poked the neg. terminal of the coil the engine reved up to normal speed and stopped sputtering. He had the timing light hooked up as well and the missing stopped and started running normally. As soon as he took it off it started running poorly again. I thought it might be a bad coil so I replaced it. But the new one did the same thing. I checked the ground wires and it didn't make a difference when i jumped a new ground.
Not sure what the deal is. Any help would be greatly appreciated.
1975 CJ5 Levi Edition, 304 V8 AMC; Blue with denim seats.
So when he probes the 'Green' coil terminal, the miss stops?
Sounds like you might need to work on that connection.
Terminals at the coil are a large problem, there isn't a summer goes by without me replacing two or three coil connectors because they give up.
I even had a problem with a new connector; one of the metal terminals had popped out of place and I didn't realize it. The Jeep wouldn't start. I went back to check the basics and happened to notice that the new coil connector had crapped out. It was esay enough to fix, but unfortunate that a new part malfuncitoned.
"I give you a republic, if you can keep it." - Benjamin Franklin
If you Jeep does not have the ballast resistor, Chances are it never had one. My 82 never had one in the system.
'78 to '86 Jeeps (and beyond) all had ignition resistors.
It is a wire in the harness instead of the ceramic block most people are used to seeing.
Motorcraft/Duraspark won't live without one.
1.35 Ohms or better...
I wish someone had answer for this problem, I have the exact same symtom, 1975 cj w/258 prestolite ignition, I have replaced gas fouled plugs, replaced carb power valve, coil, module twice, distributor, added 3 grounds, isolated the alternator (rfi). When I touch test light to the neg side of coil the engine will start and run normal, without the test light it is hard starting, rough running, irratic ignition. All of the coils I have seen listed are USE WITH EXTERNAL RESISTOR. This ignition doesn't seem to use an external ballast or resistor wire, so im still at a loss as to why it shouldn't have a internal resistor coil installed.
While it was at the mechanics he was poking around with his voltage tester and found that when he poked the neg. terminal of the coil the engine reved up to normal speed and stopped sputtering. He had the timing light hooked up as well and the missing stopped and started running normally. As soon as he took it off it started running poorly again.
can the mechanic repeat his 'success' ?? then use that to narrow down what causes the improvement