Fuel pump not running correctly... HELP

distortedworlds

New member
I've got a 1993 Jeep Cherokee Country 4.0L that's been sitting for a while with what I thought was a bad fuel pump... Here's the story.

It started having issues starting, especially when it was cold. When it did run, it would often have trouble accelerating. Eventually it would just refuse to start for weeks on end, and then randomly start up again. Finally, after a month or so of not starting at all, I tried banging on the gas tank while my buddy cranked her, and she started. The mechanic I took it to confirmed that it was probably the fuel pump, but being that I didn't want to pay $500 for the job, I decided to do it myself.

I dropped the tank, replaced the pump (correctly, to the best of my knowledge), and tried to start it again... Still wouldn't start. I checked the sparks, they were good; then checked the fuel pressure... none. So based on this information, the issue seems to be within the fuel system. I then replaced the fuel filter and the pump relay... Still nothing. So I started paying specific attention to the sound of the pump itself when I turn the car ON (not starting). From what I understand, it's supposed to make a sound for a few seconds, then stop. Mine only makes that sound for maybe half a second. And here's the funny thing. After like the second or third time I turn my car on and off, the pump stopped making the sound altogether...

I thought maybe the auto shop gave me a faulty pump, so I exchanged it for a new one. After a reinstallation, the jeep STILL won't start... And the fuel pump makes the noise only every so often when I turn the key to ON, maybe less than half the time...

So I'm thinking it may have something to do with the electrical system going to the pump itself... perhaps it's getting current but not enough? Anyway, I am absolutely stumped here... Can anybody help?

Sorry for the long post, but thanks in advance
 

first thing would be to check the electrical connections.
Check with a voltmeter what happens when you try to start, does it get the 12V or not?
if not, start looking backwards and see where is the faulty area.
Saar.
 
You most likely wont have power comming to the pump and if you dont change the Crank position sensor very common the wires will brake at the sensor get someone to lightly pull on the wires as you crank it and see if it starts
 
The crank position sensor is located at the top driver side of the bell housing and the connector is at the back of the intake
 

The crank position sensor is located at the top driver side of the bell housing and the connector is at the back of the intake


if there is a bad connection here at the crank position sensor would that make the check engine light not come on?
 
Hi. All. ! Might. I. Suggest. - You. Read. My. POST. Under. - Fuel. Pump. Electrical. Issue? There. Should. Be. Some. Info>Tips. There - - Hope it. Helps - GOOD. LUCK. JB
 
If its making a buzzing sound when you turn key it's working
check / clean TCM/ECM may have dirty connections
 
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