xj no spark and lots of swearing

[xjweeble]

OK WTF is going on with this jeep.

1995 XJ sport 4.0 auto 86K miles
Was driving along and it quit. I took out the cps to find the wires broke off replaced that with an advanced auto parts CPS. Along with i replaces all the big underhood fuses and relays. Still no spark. So for the heck of it i did a new cap, wires, and the hall effect sensor under the cap. No spark.

The self diagnostic is sending me a code 11 wich is a "No crank reference signal ). SO i wind up having the dealership scan it. They tell me new ECU. Insalled that and yet still no spark and still code 11.

After calling 20 or so dealerships i discover the chrysler ECU dont like no OEM parts. Get the new OEM Crank position sensor. And yet still no spark. When testing the 3 wire comming outa the cps

Center wire (ground) 13 volts constant
other wire 7.4 volts constant
The third wire thats i hear is suposed to change voltage as the engine cranks reads a steady 2.45 volts. The advanced auto CPS read the same but the third wire read 1.45 votls.

Any help or insite on how to fix or completly destoy this jeep would be super

[mmagnumpi9]

We had a similar problem. XJ cut out while driving and wouldnt start. Checked it out and it wasnt getting any spark, we replaced the plugs, wires, distributer, cps and a bunch of other small stuff . . . ended up being the entire coil that was shot. Once we replaced that it fired right up. (we never had it scanned though).

Might want to check that out if you havent.

[xjweeble]

new coil tonight gave me no spark
on the 1995 with a new computer would i need to program that?

[axle]

Does it have a ballist resistor?

[justjosh]

axle said:

Does it have a ballist resistor?

I was waiting for someone to say that... ;D

[sidriptide]

the 95 doesnt have a ballast resistor. i am inclined to think its the coil. go here www.NAXJA.org and do a search on "no start" and read every thread that comes up.

[xjweeble]

xjweeble said:

new coil tonight gave me no spark
on the 1995 with a new computer would i need to program that?

Me and my mechanic have come to the conclusion that its a short somewhere in a wire or a sensor, causing the CPS to give a steady 2.45 volts. Hes got all kinds of cool scopes and crap so ill let him have all the fun. I will post back and let everyone know who was the guilty party.

[jps4jeep]

I think I have a stock coil, your for the price of shipping.

[xjweeble]

Still not fixed. i have found out with that my CPS is getting 3 volts to many. So the stray 3 volts in my system is fooling my CPS causing my ECU to not function correctly. Finding the 3 volts feeding back through the sensor is proving to be, well sucky. Anyone ever have this issue. If so how did you go about tracking down the stray Volts

[dsgray16]

axle said:

Does it have a ballist resistor?

hahahahah, that'l do it



my bobby is saying maybe you need a whole new wiring harness.......or mayb eits shorted out somewhwere??

[bluerocket]

Yeaaa, I think the mechanic its at knows a damn sight more than I do. He is really good and does all my parents work.

[JeepTJ00]

Take a look at this... Ken (a great tech at my work) said this to me in responce to your post.


OK. I'm trying to remember this stright from memory, but here goes. The orange wire is the 8 volt feed. That seems to be ok, judging by first post.
The "middle" wire, as he called it, should be the sensor ground circuit, which is shared with lots of other stuff. Sounds like a short to voltage on the sensor ground circuit, but I would like to check readings myself before I said that for certain. Tell him to check the engine harness at the back of the rocker cover. They chaffe on the head bolts.


Bob