We just got a new auto zone here. As far as I know the only place in town to check your fuel pressure free. I guess you pay full price, about $50, then get a full refund when you return it. If I got that right.

A vacuum pump is less expensive, but as I understand you need an analogue meter, (with a needle), to see the "sweep" . There are less complete tests you can do with a digital. See under the fourth one down, 'sensor diagnostics" > https://www.cherokeeforum.com/f51/he...ix-links-1397/

 

You don't need a vacuum pump to check the voltage out the rear of that resistor, on the wire that goes right to the fuel pump. Ground the black lead from your meter, (valve cover or some metal somewhere.) Set it on 20, (usually the correct DC scale), then watch the meter right when the ignition is turned on.

It only powers the pump, (you should hear it running) for about 2 seconds when the key is first turned on. You can certainly bypass that resistor. It just knocks the voltage down a tad, mostly to quiet the pump some.

 

I now realize my volt metre is broken gonna get a new one and try all that again. Just wanna say now thank you so much for all the advise.

 

Could this be a faulty fuel pump? And if so how could I check that?

 

Step 1: Listen for fuel pump to prime when the key is turned to the ON position.

...if yes...

Step 2: Rent fuel pressure gauge and attach to valve on fuel rail.

 

I tried to check the map sense and i might be doing something wrong but i wasn't getting any readings froom it. I also tried checking for fuel pressure by turning the key to the on position, i heard the fuel pump turn on for about 2 seconds then i pushed in on the release valve on the fuel rail and no gas came out. do i have a defective fuel pump? or would a bad map sensor do this to me?

 

MAP sensor wouldn't cause no fuel pressure......

 

It's normal that it only runs a couple secs. It will start running again after it starts. (or while cranking)

If you hear the pump run but have no pressure at the rail, thinking a few things. Boy, pinching off the return line off the regulator, (there on the front of the rail looks like a pain.) Me, I might pull the metal line off it and just put my thumb on it. A little dangerous, that.

Then, the filter, Have you checked it? Then, there is a line inside the tank that can mess up, you'd find that if you go to change it.

And last...once my drive pin from the shaft to the impeller in the pump sheared. I could hear it running, but of course it would not pump. I'd check the filter first!

 

The filter is new I replaced that. I took another look at the pump and found out that the wires on the harness are in pretty rough shape I didn't notice when I put the new pump in. I'm going to replace that and see if it'll fire up I'll let you guys know what happens. I really appreciate all the advise you've given me I've learnt a lot thank you.

 

If you can hear the pump running, it is getting power. Jump from the battery pos to the unplugged wire off the rear of that resistor. Check the schrader valve on the rail again, while the pump is running. Besides the FPR and the impeller pin, see that is simply not leaking, running out somewhere. No smoking!

Are you sure there is enough gas in the tank?

 

Had someone try cranking it over while I checked the a schrader valve and there was no gas so I unplugged the line right from the pump and nothing came out. It did a few days ago but now there's nothing. I hear a buzzing coming from the tank

 

Fuel pump is shot or the hose connected to the fuel pump inside the tank is shot.

 

I have a jeep that I replaced a lot of the same items. Mine had the problem of running sometimes for short time and then dying , and sometimes no start. I had it towed to a shop where they diagnosed it and found a bad shut down relay. It was the next thing on my list to change, but I was frustrated . The guy who repaired it had it shut down and he swapped the ac relay and it started right up. Might be worth a try , the new relay was about 35.00.

 

Fuel pump won't prime if the b latch relay isn't triggering

 

Assuming you have enough gas in it, you will need to pull the pump/gauge sender/float unit from the tank. You need to me careful not to knock the filter off removing it. It might just be a tube be in there from the pump to the mounting plate. Or maybe the filter is already off and the inlet is plugged. Or it did like mine and tha motor is not driving the pump "impeller" (for lack of a better word)