woolybugger226

About a week ago I got into my 93 XJ 4.0 to start it up and it stuttered really badly and died. After that it was cranking over just fine but it was not firing at all... First thing I did was check for spark and sure enough I was getting nothing..Checked all my grounds, plug wires etc. to see if anything was lose or frayed and I could not find a problem.

Searching the forum I found lots of threads where the Crankshaft positioning sensor was the usual culprit for people with this problem. So I changed it out... Nothing changed...Next I changed out the distributor cap, rotor, spark plugs and wires... Nothing changed. Finally I decided to try and replace the coil and she fired up!!.. Only problem now is she runs like crap .. It almost sounds like the timing is off for some reason now. She stutters really bad and if I dont keep my foot on the pedal, she dies. Also I noticed the Tachometer is acting really weird now.... When I start the jeep, the needle on the tach jumps to idle position like normal but as soon as hit the gas and bring the revs up, the needle just stays bouncing at 1000-1300 rpm no matter how much gas I give it or how high i rev it... It stays at 1000-1300 rpm even though I know for a fact i am upwards of 3000-4000 rpm. Could this be a computer problem or possibly the distributor?? Any suggestions or advice would be appreciated.

Kingfisher

Could you have crossed plug wires?

woolybugger226

At first I thought that might be the problem. The wiring is correct though. I went over it a few times to make sure. Used the diagram in the FSM. Also as a precaution, before I replaced the old wires with the new ones, I took a good picture of the cap and the wires to compare with after I was done.

I think whatever part or sensor that is tweaking out my tachometer is probably the culprit to my ignition problem.

Does anybody know where the tach signal comes from?? I assume it comes from the ECU/PCM... but where does the ecu/pcm get the tach signal from??