Ls1Powerz

okay i bought this 87 xj for $400 so i dont expect it to be perfect so this is the one flaw i have found. the jeep starts slow but does start. I can drive it for hours but as soon as it gets to about 210* or so and stay there for a while it dies under the slightest acceleration and then i can crank and crank on it and nothing will happen but the occasional massive backfire. Then it will start and i can drive it for about a mile then it will happen again. If i let it cool off completely the process will start all over.

I was told this could be a CKPS? It has a flowmaster 50 series on it so i was thinking maybe the exhaust has too much back pressure due to the cat engorging once it gets hot. (I was a mechanic for 3 years and i have a fully built ls1 camaro making close to 500whp that was daily driven for a while, so i am mechanically inclined i just dont know anything about jeep lol) So i dont want to end up replacing the wrong part and be out the $30 for the CKPS and that not fix it. So if anyone has had any of the same issues and figured out why please fill me in on the blanks.

Thank you

TrekkerJmm

Hi and welcome to CF...It could be the CPS or vapor lock on the fuel rail. You can test the CPS by checking out the diagram I have posted...Tj

jeepboy4life

also check your throttle control sensor

Ls1Powerz

Thanks for the input guys but if the problem is intermittent then will it still show with that test?

Ls1Powerz

Bump.

Morat

Well, the problem will only show when it is occurring - which is what makes diagnosing intermittent problems such a *****

Ls1Powerz

Well i have to agree with you completely there... So i guess my options are to drive the thing for hours and have an ohm meter on hand or just replace the $20 part and see if anything else happens... so far i need to replace the steering stabilizer and the CKPS. not bad for a $400 steal lol oh and i am bed lining it with my own little touch :]

Ls1Powerz

UPDATE! Changed my CPS which is a pain is the A$$ btw. And as far as i know it fixed my issues. I drove it for about 4 hours straight yesterday with no problems! Thanks again guys!