Need y'all's help!!

elistwrt

NAXJA Forum User
Location
Lake Charles, LA
I have a 1997 Jeep Cherokee Sport 4.0L 4x4 Auto. A few weeks ago I started the Jeep drove 50 yards and it died and would no start back up.

Back story- a few weeks before the issues my battery was not holding a charge very well and a light was left on so I jumped it off and when it started it revved up to 2000 RPMs and stuck so I turned it off and restarted and drove it home. Next morning I got a new battery.

Back to now- Initially I had crank, no start, and P0320. I changed the crankshaft position sensor with a aftermarket sensor and got the same symptoms, so I ordered an OEM sensor. While I was waiting on the Mopar sensor. I updated the grounds and cleaned up the ignition coil supply on the wiring harness. I then checked for spark and fuel. I had spark and no fuel. I pulled the codes again and the p0320 was gone but got P1389. I moved the relays around and I lost all of my instrument panel and the constant power to my radio. I installed the Mopar sensor and still nothing.

All of the fuses and relays are good. Has spark but no fuel at the schrauder valve but the fuel pump is priming.

I'll post a video of the spark.

Any help will be greatly appreciated, I am stationed in Louisiana and I have to pick my kids up for their Xmas visit in 2 weeks in Florida. So I NEED this thing back on the road!!!

Thank you guys and gals,
 
The initial P0320 may have been a bad CPS connection coincidental to your fuel problem. Try erasing all codes before proceeding..

Low/no rail pressure can be an injector which is leaking fuel into a cylinder, a leak in the fuel line, a bad pump/[COLOR=blue !important][FONT=inherit !important][COLOR=blue !important][FONT=inherit !important]check [/FONT][COLOR=blue !important][FONT=inherit !important]valve[/FONT][/COLOR][/FONT][/COLOR][/COLOR], or a combination of those things.

I ran into this same fuel pressure problem last year. It turned out to be a leaky fuel line which ran alongside the intake manifold. It rubbed against a mounting bracket, developing a small leak that became worse over time; it dripped just enough to drop pressure to zero quickly, but did not leave a puddle underneath, as it "sprayed" fuel up underneath the air filter box and evaporated within a few minutes.
 
By fuel pump priming, you mean you can hear the pump run for 3 seconds when you turn the key on? If someone is cranking it, you get no fuel from the Schroeder valve?

My code app shows P1389 says Auto shutdown relay sense voltage.

You could try starting it on spray start. If that lets it run, you have verified that it is a fuel issue.
 
Thanks for the reply!

Yes I can hear the fuel pump run for 3 seconds or so when key is turned on, and yes there is no fuel at the Schrader valve.

I'll give the spray start a try in the morning.
 
So I was thinking can efi vehicle run on spray? And there isn't an external fuel filter on this thing..

But I disconnected the fuel line at the fuel rail and didn't get anything..
 
Efi still runs on spray. Disconnect air inlet tube at throttle body. Don't remember on Jeeps, but most efi have filter underneath a couple of feet in front of tank attached to frame or body. Usually need little plastic tool to disconnect.
 
The 97+ have the filter on the pump assembly in the tank. If you can hear the pump run and no pressure at the rail I'm going to guess that the rubber hoses that attach the pump to the bung on the tank are deteriorated and the fuel is just spraying inside the tank on prime. I had this happen on a MJ that I bought for $250 due to the owner giving up finding the fuel pressure problem. Easy fix!
 
The 97+ have the filter on the pump assembly in the tank. If you can hear the pump run and no pressure at the rail I'm going to guess that the rubber hoses that attach the pump to the bung on the tank are deteriorated and the fuel is just spraying inside the tank on prime. I had this happen on a MJ that I bought for $250 due to the owner giving up finding the fuel pressure problem. Easy fix!

What did you use for the fix? I'm gonna drop the tank when I get home and snoop around hopefully that is the no fuel issue.

But that's still leaves me with no dash, no acc power, and a P1389 diagnostic code.
 
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