Went to go to work today and my jeep wouldn't start it cranks but doesn't even attempt to stumble. First thing I did was push on all my spark wires, nope, then checked for fuel pressure at the release valve on the rail. Only a dribble of fuel came out which it should SPRAY out yes? I then got back in and listened when I turned the key I can hear the fuel pump going like it always has.

So little to no fuel pressure, fuel pump IS going, I just changed the fuel filter a few months ago.
Supposedly the p.o changed the fuel pump a few months before I got it, so not more than 6 months ago.

Ideas please?

Clogged fuel line or pump?
Fuel filter clogged that fast?
Could the fuel pressure regulator cause this?
Some other relay or something?

First thing I'm gonna do is pull the fuel filter off and see if its clogged, but right now I'm looking for other ideas to check if that's not the problem.

Thanks!

 

I just finished my fuel pump project this morning. Go read my last entry. I assembled everyone's advise into step by step instructions. It's quick and easy. When you turn the key on you can hear the pump. If not, either no power to pump or it's shot.

Swap in two different relays to make sure it isn't something simple before you attack the pump.

If no run, pull the three pin plug apart next to the filter and test the pins for 12v. It will only read 12v for two seconds, then zip. SOmebody has to key the ignition for you so you can read it. Leave it off ten seconds between attempts. Make SURE you have 12v. If not, you have a elect. problem If you have 12v, bad pump.

 

If you would have read my post I said I can hear the pump fine like it always has, when you first turn the key it hums for about 2 seconds.

I was talking to someone and they said the hoses at the pump could have cracked and its not building pressure.

Since the pump is running its not going to be a relay right?

Ill have no problem getting to the fuel pump if thats the case, I was just seeing if there was anything I didn't know about on these cars or forgot.

 

anyone else?

 

really? thanks guys...

 

It sounds like you got it covered... no fuel pressure, replace pump. -E

 

I had the same problem with my 93. there is a little plastic propeller inside the pump that keeps the fuel flow(from what my old mechanic told me at least) and I guess a piece of rust from my tank went through and broke that propeller? So just like you, I heard it prime but no fuel coming from the tank. Id change the fuel pressure regulator too.

 

So can a bad fpr cause it to not have pressure at all?
And yeah I was just hoping that since I heard the pump it would be something else that I didn't have to drop the tank, oh wells.

 

i need to know if the fpr will cause this... before i go taking the tank off

 

You don't have to drop the tank to replace the fuel pump. It is on the front side of the tank and you can get to it with out droping it.

 

He is right the older XJs have an external fuel pump where the newer ones its all inside the tank.

 

Was looking at your photos. I wish my 89 looked that good. I paid alot more than you did too. Very nice! Good luck with your fuel issue.

BIH

 

you dont necessarily need to drop the tank but i would recommend it. its a big pain doing it without dropping it believe me i did it twice. i just cut my brackets off, heated up the nuts to get them off and welded them back together when it was time to put the tank back in place. my fpr went as well and my jeep wouldnt stay on my line was constantly just filled with air

 

Next time put some carb cleaner down the throttle body this will let you know if no fuel. Keep and old spark plug in your tool box to check for spark, this way it is easier to check.

 

If the previous owner replaced the pump then that is where I would start. I have a 89 that would start and idle fine but would die as soon as I hit the throttle. Did all the normal checks, spark, TPS sensor, fuel pressure, blah blah blah. It finally decided not to start any more with no fuel pressure. I started at the fuel rail and worke backward toward the pump. No pressure at the rail so I moved to the filter outlet with no luck, then to the fuel filter inlet with no luck, last in line was the pump. After many hours of chasing gremlins I found that the PO did not secure the hose for the fuel pick up tube and it slipped off inside the tank. Two quick turns of a screwdiver and it fired right up and had full and immediate throttle response. Check all the simple things first.