Sword

I had previously fixed my GF's jeep (https://www.cherokeeforum.com/f2/200...unning-268128/) a few months ago that was dying, I changed the crankshaft position sensor and it seemed to be working since then. Today we had a new problem, it was mostly the same symptoms, except one big one, the jeep was stuttering and running rough and the engine was seeming more quiet than normal (not a good quiet), and the other initial symptoms were the same: loss of engine power (electronics were still on), power steering was gone and accelerator did not work. Got it pulled over, and had a pretty intense tow home, but its back here. The starter cranks but the engine does not start.

From what I read online, some people had problems with the camshaft position sensor, bought a new one and slapped that in today and with a blown fuse mentioned below, it seemed to work - for just a little.

Some other clues, I found a blown fuse in 'slot 18' in the engine bay - online mentions something about the ignition rail and injectors. I put a new fuse in, and it started up just fine. Drove about 50 yards, then it died. Fuse was blown again.

I had a scanner and it was code P0351 GENERIC Ignition coil A Primary/Secondary circuit.

Where should I start? Was swapping the camshaft useful at all, or can I go back to the old one? Where do I start with checking the injectors vs the ignition? I had previously replaced the fuel rail last year and cleaned the injectors; and I also changed the coil pack last year also. Are there any relays that might be going bad?

Thanks

Sword

Did some more testing today. Looked pretty thoroughly and didn't see and frayed or rubbed wires.

I did the following test, given that fuse 18 was blowing, someone in a different topic recommended using a test light and shaking things, I dont have a test light, but had a multimeter so wanted to see what the voltage did. The voltage showed zero without the key in, when I turned the key to power, the multimeter spiked up to around 9 before dropping back to zero. When I cranked, it stayed at zero, but after the crank spiked up again before dropping to zero.

tech

I would try a new coils because you have a coil code and go from there .

Sword

While I get a new one going, two other questions, when I take the old one off would there be any clue to something going wrong if I look at the spark plugs?

I also took my asd relay off and tested it by hooking it up and it buzzes, I was expecting a solid on/off. I tried with the fan relay and it buzzed too, but I have had problems with it in the past. Is this typical if I direct wire them into the battery?

tech

Because of the way the coils are made the only thing you can do is ohm the coils there are 3 coils .

Sword

I ran the test from here:https://www.cherokeeforum.com/f2/tes...l-rail-204328/

I was getting .6 on pin 1, and the other two pins were 1.2 and 1.4. Would an extra ohm there be enough to blow the fuse? I tried checking the 2nd part of the test, from pin 2 to the spark plugs and was not getting anything. No continunity, nor any resistance.

tech

You can ohm the coils at the wiring plug just like you would ohm any other coils but I don't know what the specs. are but if you ohm it and one is different then the others then it is probably the bad coil .

Sword

Was doing some more electric testing.

According to that link the spark plug boots should be 15k. What is the correct way to test, I had the probe on the the 2 pin and tried every plug, tried every other pin and the plugs, and plugs to plugs and wasnt getting anything.

I am getting continuity from the asd relay to the fuse, and from the fuse to both the ignition rail plug, and also to the capacitor plug. I was trying to get a reading through the capacitor and was not getting anything, should I be?

Edit I hooked up the coil to the battery and ground the plug and cranked the starter, I was NOT getting spark at the first coil, but was getting it at the 2nd, so seemed conclusive something was going wrong with the coil.

Sword

Well I got a new ignintion coil pack from this 'AA automotive' - unfortunately I see its made in china, prob why the last one died. But tried the sparkplug test and it sparks, I put it in and the jeep fired up. So I think its good to go now, but still really wary about the china rail.