91' Jeep Cherokee Fuel Pressure Issues

skidog74

New member
First of all, I do not know what else to do! New inline 6cyl motor (rebuilt), new fuel pump (3-times), new fuel filter (the right way). Replaced fuel pressure regulator, cleaned all injectors, vacuum lines blew out. I could not get to start so I paid to get a diagnosis, which came out being $700 (10 hrs.) to figure out it was a ground issue why it did not start. Needless to say, this is what I get for trusting a Mechanic who I dont know.

So now the jeep starts and it "purrs". For about 10-15 seconds, then dies. Put a fuel pressure gauge on it and it is 10-12 psi. My 95' jeep wrangler is at 37 psi for the same exact motor. No clue where to start or what to do. Could it be the ECM which they did mess with the brain a little bit when they were doing the 10 hr diagnosis. Could I take the ECM from the 95 jeep wrangler and put on the 91 cherokee? Vacuum lines? It is fuel injection. Please help.

In advance, I am not a mechanic so excuse my ignorance. This has turned out to be an expensive ass hobby, but I will love the outcome!

The first pic is the 91 cherokee which will be mad maxed out after I get running. The other 3 are my jeep wrangler.
 

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WJCO

Meme King
First of all, I do not know what else to do! New inline 6cyl motor (rebuilt), new fuel pump (3-times), new fuel filter (the right way). Replaced fuel pressure regulator, cleaned all injectors, vacuum lines blew out. I could not get to start so I paid to get a diagnosis, which came out being $700 (10 hrs.) to figure out it was a ground issue why it did not start. Needless to say, this is what I get for trusting a Mechanic who I dont know.

So now the jeep starts and it "purrs". For about 10-15 seconds, then dies. Put a fuel pressure gauge on it and it is 10-12 psi. My 95' jeep wrangler is at 37 psi for the same exact motor. No clue where to start or what to do. Could it be the ECM which they did mess with the brain a little bit when they were doing the 10 hr diagnosis. Could I take the ECM from the 95 jeep wrangler and put on the 91 cherokee? Vacuum lines? It is fuel injection. Please help.

In advance, I am not a mechanic so excuse my ignorance. This has turned out to be an expensive ass hobby, but I will love the outcome!

The first pic is the 91 cherokee which will be mad maxed out after I get running. The other 3 are my jeep wrangler.
Is it throttle body injection or port fuel injection?
 

J&k_Overland

Active Member
Fuel pump. Surprised it even starts with that low a pressure Pretty easy to get to don’t have to drop the tank
 
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