Rip 89 Xj

Hey i dont post here to often, just do a lot of reading on this site, but i have come to you guys with a question. Well its official my xj has past away. So far i cant figure out the problem, a shop in my town cant figure out the problem, and the stealership cant figure out the problem. the only thing i know is that the injectors arent purging. IF you throw fuel down the intake it will run for about 15 seconds and then die. It has spark and Fuel at 40 PSI in the rail. The dealership said its a POS and i should junk it and that they could re wire then entire car for 1000 bucks(rip off) or buy a new jeep. So my goal is to look for a 91-96 Xj and re build it. take the parts of of mine that are good, ie brakes, suspension, tires wheels. Stereo. But here are my questions, does anybody know why my injectors arent purging? i fugre ill ask to see if anyone knows before i start parting it out. also all NY NJ PA CT xjers keep your eyes out for a new Xj for me looking to spend about a grand. Thanks guys

Injectors are driven individually from the computer (ECU). It should be pretty easy to rent/borrow a set of noid lights that hook between the harness and the injectors. They allow you to see if the injectors are firing. If they are not getting any power, there is a connector that routinely causes problems called C101. It is mounted on the firewall above the brake booster. It can be causing the problems. There are pretty much only three things that can cause this if your fuel pressure is actually 40psi. You can have a bad ECU, bad wires, or bad injectors. It would take all the injectors going bad at the same time for it to be injectors, so that is not likely. That analogy is somewhat the same for the connector theory, leaving the ECU or the connector actually at the ECU. If it is an ECU for a manual tranny, I have one and we can maybe work out something, or check around if anybody closer has one they can loan you. It would only take a minute to swap it in.

PS, the mechanics are lazy and stuipid. They have forgotten how to troubleshoot a problem if their scan tools don't tell them what to change. The Renix system does not provide for ODB connection so they would have to have the older dedicated scanner.

Don't let anybody talk you into changing the CPS or the cam postion sensor. If it fires when you pour gas down the intake, they are fine. It is possible that the MAP sensor is disconnected/bad or the TPS is flakey. They can rarely cause similar symptoms by fooling the computer into shutting down the injectors.

thats already really good info i will look into that, any other ideas keep em coming

Edit: I have 4 brand new injectors that were replaced sometime last winter. So i belileive the injecotrs are good. ALos i have a really bad rear main seal leak. Do u think the opil could have possibly shorted anything out?

xj89 said:

thats already really good info i will look into that, any other ideas keep em coming

Edit: I have 4 brand new injectors that were replaced sometime last winter. So i belileive the injecotrs are good. ALos i have a really bad rear main seal leak. Do u think the opil could have possibly shorted anything out?

Click to expand...

Not likely.