wow another XJ wont start

[xjweeble]

Ok got the mopar CPS from jeep and still no spark. CPS reads good ground 7 volts power to and 2.4 volts on the third wire


Anyone know how the autoshutdown relay works?

 

[xjweeble]

Would the new ECU i installed need to be programed?

 

[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

 

[Wrectec]

Do you have power at the coil? Do you have power to the Injecters? Both come from the ASD relay. Pin 30 of ASD relay should be hot at all times, pin 86 hot in run or crank, pin 85 should should ground in start or run from computer. If pin 86 not hot in run or crank suspect ignition switch or that area.

 

[langer1]

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

The power for the CPS is supplied by the ECU, it is looking like the short ruinned your ECU.

 

[xjweeble]

The short has been fixed prior to the new ECU being installed.

 

[langer1]

The short has been fixed prior to the new ECU being installed.

Well then you still got a problem with the wiring somewhere.
Have you tested the CPS voltage at the ECU and the CPS?

 

[javik]

ok, im a noob so humor me so that i understand you. Is the engine cranking over but just not fireing, or are you turning the key and getting nothing? I just spent 2 weeks on a cherokee no start and the only things i found (within reason) that will cause a no start is the CPS and the NSS, and strangely the IAC. the CPS and IAC will give a similar condition in that the engine will turn over but will not fire. THe NSS will not allow you to do anything if it goes bad, no crank/fire. But i must say that that voltage difference your describing for the Cps does sound wierd.

 

[xjweeble]

Back fromt he dead (this post as well as the jeep). After basicly everything was replaced with known good parts i started to think the dealer XXXXed with something to sell me diag and ECU. Bingo!! They had taken apart the the cps connector and switched two wires so when you test volts all it is well. Even after sitting 4 years it started right up.

 

[winterbeater]

Sometimes (often times actually) it's the simplest thing that gets you. At least you got your XJ back for the winter.

 

[SteveT]

Thanks for the closure. After dealing with a no-start myself, it's nice to read how others have resolved their issues. 4 years?...That's pretty funny.

Steve