I am still having a no spark issue with my 85 2.5L I4 Cherokee. At the rear of the engine I found two wires, one tan with white stripe and one black with yellow stripe that are not connected to anything, and I have not found anything missing wires for them to be connected to, and both have 8V on them when the ignition is in run position.

I do not think this model had the CPS, just wondering if there is anything else these could attach to. They come out of the wire loom just to the drivers side of the valve cover, the one attached to the upper firewall near the hood and are only about 10 inches long, they won't even reach across the valve cover.

The engine was running up until I changed the shocks on the front, which I am sure did not do anything to the engine, but it also had a dead battery about this time. I have replaced the ignition pickup coil and the ignition control box and still no spark. The coil was changed a few months ago, testing it with the ohm meter it seems ok, but if I rake the ground wire across the terminal I can not make it discharge a spark from the high voltage terminal. It has a constant 12volts when the ignition is in run position. The only other thing I see in the schematic is the Micro Processor Control Unit, but I am not sure where that is located and if it actually is involved in triggering the spark.

Any ideas would be much appreciated. I will be getting another coil tonight just in case.

 

Are you trying that with the OEM wire still connected to the coil (-)? You should get one spark out of the coil every time you ground the (-). If not, the coil is bad or something is holding the (-) terminal to ground all the time.

 

I was trying it by opening the OEM wire and closing it but I think now I should be using a second grounding wire.

I think the unattached wires may go to what is called the Anti Diesel relay and the PCV solenoid. But not positive about that yet, can't find the missing ends to reattach them.

I picked up a new coil today, but they gave me an Accel 8140 with the screw terminals, I think I should have gotten the 140201 listed for the Ford Duraspark with the slide on terminals. I'm not against using the one with terminals, easy to adapt, but someone online mentioned that one needs a balast resistor which my system doesn't have. Does anyone know if it really needs that to work?

 

Marking.

 

Well tried the new coil, still no spark. If I put the plug into the coil wire and take the ground terminal loose and slide it up and down the terminal screw I get a faint spark, but not easy to make it do it.

I put a volt meter on the positive side of the coil and when the ignition is on there is just over 6v there to ground, 1v negative side to ground, with everything hooked up. If I turn the starter over it goes up to 10v and 2v positive and negative. That would seem to indicate that the starter relay is working correctly in bypassing the resistor wire during cranking. Power is there to the coil, it just will not throw a spark. Makes me wish I had a way to convert it to points and not have to fool with the electronics.

Here is a photo of the two wires I found not attached to anything, the top one is the tan/white stripe one, the lower one is the black/yellow or maybe /white, not easy to tell they are so oily.



I honestly can not find anything that they would plug into, they must have been just hanging there for quite some time, but the ends seem too clean for that. The strange thing is I haven't moved anything in that area since it was running last. I did tape them up to keep them from shorting to ground though just to be safe.

The only thing left is the computer, but I am not sure where that is located.