1996 XJ just quit while driving

[MY4THJEEP]

I was making a turn when my 1996 XJ Cherokee (170K miles) started running very rough. It acted like it was running on 1 or 2 cylinders. It did not have enough power to drive it, so I shut it off... Since I was coming out of turn I immediately thought that the original fuel filter became clogged with water or dirt when I made the right hand turn. Original filter has 170K miles... Well I replaced the filter to no avail. I checked the fuel rail and had good presure and flow of fuel... As a back ground, the CPS, coil, cam shaft position sensor, plugs, rotor, and wires have been replaced recently. I have voltage (+5VDC) to both sensors.

Final clues... I am getting spark from the coil wire when the engine is cranked... However, when I plug the coil wire back into the distributor and check for spark on plug wire #1 I do not have spark. Yes, the rotor is in place and it is indexed correctly... My suspicion is that the timing chain has slipped, but I hope someone can come up with a better (less expensive) answer...

Thanks for your help...

Naples Mark

[Saudade]

How did you check for fuel pressure?

How "recently" have the sensors been changed?

[MY4THJEEP]

I checked the fuel supply at the fuel rail.

The cam shaft pos sensor was replaced after the problem occured. The crank shaft sensor was replaced 50K ago... I checked for voltage at the CPS and it was 5VDC. I also used an oscilloscope to measure the return signal from the CPS and it was producing a 0-5VDC square wave as expected.

???

[Saudade]

No, I mean did you use a fuel pressure gauge or did you just depress the schraeder and watch a bit of gas spit out? You need to use a gauge. If you did, what were the pressures?

When were the cap, rotor and wires changed out?

[2000izusu]

try renting a fuel pressure guage with a long enough hose to tape it to the windshield! this is usually free at autozone (refundable deposit).
then go driving and note the fuel pressure when the condition occurs! this will for sure rule out the fuel pump and fuel pump sock. mike

how much fuel was in your tank when this happened?

[MY4THJEEP]

No I just pressed the value and fuel came out... I will get a pressure gauge and measure the presure... Thanks...

[javatrooper]

fuel isn't the problem if there is no spark. I have the same problem. coil fires, no spark from the plugs. new everything. just got a replacement pcm today but won't be plugging it in until this weekend. Let me know if you come across anything though. good luck, this has been driving me nuts.

[jer2266]

Double check your cps sensor i recently but a new one and it turned out to be defective it happens