loveoldtrux

Never seen this one before!!

Son had to get towed home a few weeks ago as his XJ quit on the way home. He did not raise the hood to snoop around. I traveled to the XJ and lifted the hood - immediately I spotted the coil wire burned in half (we were so stunned I forgot to get a picture)! It's just a stock XJ, the coil wire was not leaning on anything. I'm almost 70 and have done a LOT of engine work / tune ups through the years and have NEVER seen this - anybody got an idea what might have caused this?

I got my son to replace the wires and plugs - still won't crank; spins over but won't start up....

Hoping you guys can help - this guy works like a dog and loves Jeeps (he has THREE including a Rubicon - I have an XJ); he needs a little bit of love,
Mark

UPDATE: we DID take a snap of the coil wire!! Just got it from son - here it is for your amazing viewing pleasure!! ---

BlueRidgeMark

"Crank" does not mean "start". Crank means the same thing in meant in Model T days - it turned over. Spins. Goes roundy round. The starter motor engaged and made the engine turn over.

I don't know how it's possible to have a wire burned in half. That's really weird.

I'd test for spark at this point, coming from the coil to the distributor. I suspect you'll find a problem in the dizzy. Possibly a short to ground?

loveoldtrux

Blureidge Mark - I bet it's NICE and cool where you're at (blueridge?..) it'a NICE 54 in Kingston, GA! Seems my son DID take a picture of this coil wire slap dab burned in half - I'll post it shortly as I'm sure lots of others haven't seen this either!!

BlueRidgeMark

That's ugly!

One thing I can think of that might do that - if the conductor broke at that point, there would have been repeated arcs and... well, you get the picture.

I'd be concerned that it compromised the coil in the process. Mebbe not, but I'd check....

loveoldtrux

Just replaced the coil - still no start up. Will have to travel to son's house this morning to see what's going on.

cruiser54

That cap and wire look older than dirt.

Supposed to replace cap, rotor, wires, and plugs every 30,000 miles. Maintenance.

dave1123

Extremely high resistance can burn up electrical connections without blowing fuses. It seems the high voltage arcing burnt up the whole wire. The coil may be damaged from the heat and/or the cam sensor from the high voltage having nowhere to go except back into the sensor.

loveoldtrux

Cruiser - thanks for the most excellent analysis and feedback. Just replaced the items you listed.

loveoldtrux

BlueRidgeMark - ended up replacing the coil and then connecting the plug wires to the CORRECT plugs and it started up on the 2nd spin. Thanks for the help - this post can be closed.

cruiser54

Thanks for the update!!!

BlueRidgeMark

Hee hee!

You aren't the first one of us to be burned by that!