I have an 87 Wrangler with the 258. It was running fine, I shut it off and now it refuses to start. It turns over fine and fires once then dies. The engine is getting fuel, and it is sparking. I checked the spark with one of those inline light things, and the sparks seems to die off as soon as it fires and I stop cranking. I dont have a clue what to check next except for timing but i dont think that would have just got off. Also I did the nutter bypass a few years back so i no longer have a computer.


Thanks for any help

Sounds like the resistor has failed.. It is a spring looking thing that supplies voltage to the coil after starting.. The starting circuit sends 12 volts from the key and the resistor sends bout 6 or 8 volts after the key is turned to the run position.
Put it in run and check the coil for voltage..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

I checked the voltage with the key on like you said and there is no voltage at the coil. So where is the resistor located at on the vehicle.

Should be in front of the drivers knees under the hood on the firewall.
It is a small ceramic thingy with a wire on each end. One end should have 12V when the key is ON and the other should have 6V or so..
Inside is a spring looking thing that reduces the voltage.. When the spring goes away so does the voltage.
In the olden days we changed ballast resistors when we changed the coil.. I have known guys that carried EXTRA ballast resistors in their vehicles.
You can check it by running a jumper from the 12V side directly to the input side of the coil...if it runs then the problem is the resistor..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

I looked all over the firewall and cannot find the stupid thing. I went to the parts store to get a new one, just to make sure I was looking for the right thing and they dont list my jeep as having a ballast resistor. Was it combined with somthing else that year? I did run a jumper to the input side of the coil and it fired right up.

Well they were discontinued. If none is listed for your jeep, and you cannot find one on the firewall then your problem is somewhere else.
Is there anything else that does not lite up in the run position?
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

Nope everything else works just fine, I was thinking finding a 12V source(key on) and using a ballast resistor to bring down the voltage to 6V, and splice it into the input side of the coil. I realize this is a bandaid and doesnt fix the real problem but Im sick of not having a vehicle.