I need some serious help. I have an 89 xj, I bought it not running. I've fixed some problems and am now stuck. It won't start and when it does it revs to 3k and dies right away. I have fuel and spark and compression.

New parts:
fuel pump
fuel filter
alternator
distributor cap and rotor
plus and wires
ignition coil

I bought it knowing it needed a fuel pump. Replaced that and the fuel filter, and got fuel to the fuel rail. That's where my problem started. I have exhausted my knowledge. I took it to a Jeep place, they wanted to replace all the parts I just mentioned without knowing if it would start after. I replaced all of them and am in the same place.
Any ideas and help would be appreciated.

 

Clean your battery terminals... Both the battery and the wire connectors.

 

I'd look for a vacuum leak, particularly around the intake manifold.

 

Right at the firewall driver side by the fuel injector, look for a little wire that has the insulation rubbed off and grounding out. Its the crank position sensor. It gets hot and melts and grounds out. This was me about a month ago. It would cut out while driving. And when I'd go to start it, it would crank and just die after turning over.

Or read this to test it out. You can find the location of the wire in this post too.

https://www.cherokeeforum.com/f51/testing-cps-5563/

Thanks BlueXJ.

 

X2 for this as well.

 

Click on the link in my signature and do Tips 1,3,4, and 5 before wasting any more time.

 

New battery and new terminals.

 

I tried looking for it, no burns or melting in those wires, I'll test it tomorrow. I tried to start it and now it will run at a very low idle (well below 1000) but it stays running. When you touch the gas it dies but will start back up... I'm really confused at this point. Any ideas?

 

I've replaced the vacuum lines and hoses, how do I check the manifold for leaks?

 

lol my bad, New battery, wire connectors, and negative wire. Positive is still in good shape.