Hello everyone,
I have an all stock 2000 XJ 4.0 that is giving me some trouble. I have had it for roughly a year and it has ran flawless until now. I fired it up and left my house and it cut off at the end of my driveway. It started right back up and made it about an 1/8 mile before it just shut off. It didn’t sputter at all. At the time I didn’t have a fuel pressure gauge so I tried to check the basics. It had spark and all the fuses were intact. I gave it a bump of ether and it fired up so I assumed it was the fuel pump. I replaced the fuel pump and nothing changed. I bought a fuel pressure gauge and it has 49 psi at the rail. When cranking, the tach is not reading and it’s not throwing any codes. The most random thing is that I left the key on for a few minutes while we were standing around and I heard a relay or something click under the hood. I tried to start it and it ran for roughly 20 seconds and then died and wouldn’t start back. I couldn’t get it to replicate this scenario. The battery is fully charged. I’m stumped, any ideas or directions to look?

 

Check for injector pulse if you have fuel pressure and spark.

Also, get some sandpaper and clean the ground points. There are hundreds of threads with instructions on how to clean the grounds and their locations.

 

Thank you. I will start with these and go from there. Do I need to purchase a noid light or can the pulse be checked with a meter?

 

Usually a multimeter doesn't have a fast enough refresh rate to show that, but you can check for the +12v on one side of the 2 pin connector. The ECU pulses ground to the injectors. Noid lights are great, but as long as I've been a tech I have never used a set. They're too... specific. I like using a logic probe. It's way more versatile, and HF has them for like $20.

 

Finally had time to get back to work on my issue. It ended up being the crank sensor. It seems strange that it would run on starting fluid with a bad crank sensor but that was definitely the problem. Thanks for all that helped with the diagnosis.