View Full Version : calling out jeep gurus

11-23-2009, 06:24 PM
just picked up a 90 xj 4 inch lift inline 6 for free only thing is wont start guy had it running one night shut it off then wouldn't start after that so i got it home and started to look at it its got fuel to the injectors and it has a spark although the spark looks weak but im not sure what it could be like i said has fuel and spark and it turns over and sounds like it trys to fire every once in a while but no go so anyone have any idea i could try please let me know[36] [36]

11-23-2009, 06:30 PM
simple way to check some fuel issues is, disconnect the fuel resistor (by the air box,and run a jumper between the connections) then run a jumper between the 30 prong and 87 i think it is, on the relay. it should run the fuel pump full time(you should hear it running. check which one is the full power prong, then jump it to the connection across from it). then try to start it. if it runs, you know you have a problem with fuel pump wiring. if it still doesnt run then its other problems. it could be alot of things, but there is alot of cheap or free methods to test various things on a renix jeep (thankfully you can disconnect most things and stuff on a renix and it still will run, awsome for diagnosing problems)

11-23-2009, 06:38 PM
Could be the crank position sensor (located at top of bellhousing) try unplugging it and plugging it back in . Its a bugger to change,no room to get in there. I think I used a 11mm 1/4 inch socket, and a few extentions from the bottom side to get the two bolts out that hold it in,and careful not to drop them!

11-23-2009, 10:03 PM
i thaught it might be the css but wanted to hear other things to try first because i know its a pain to change

11-24-2009, 05:22 PM

11-24-2009, 05:59 PM
you got injector pulse?

11-25-2009, 10:29 AM

11-25-2009, 11:08 PM
if it fires at all it wont be CPS .........................................

11-26-2009, 02:27 PM
ive had the cps work some times, not other times. it can be effected by heat.

11-26-2009, 03:08 PM
if it fires at all it wont be CPS .........................................

Who told you that? They were wrong!