doinwork34

Hey guys, first post here...
So Ive been having problems with my fuel pump lately.
I have a Cherokee '91 4.0L I6
Backstory: For the last month or so my jeep was hardstarting, finally figured it was the fuel pump (eventhough pump sounded healthy with a deep buzz for about 1 second) attempted to replace it but when I pulled the old one out of the tank I found the 8in rubber hose was extremely loose on the end attached to the pump and actually slipped off as soon as I grabbed it! Fixed that and my jeep started right up.

Then today (a week later) Im driving to work, and it suddendly dies on me while trying to acclerate from a stopsign. I role to the side of the road and turn the power back on to see if I hear the fuel pump...And I hear it "click" on and 1 second later "click" off with no buzz noise. I popped the pump out again to see if something came loose and everything looked good. I also made sure I had gas (quarter tank) So...whats the problem? did it finally die and it was just quincedental that I fixed it a week ago?
Also when I did try to turn it over, there was no sputtering or anything it just would turnover at all.

Hope I can get some feedback! Thanks!

RTorrez1

You need to start by going to the auto parts store and rent a mechanical fuel pressure gauge and check you pressure at the fuel rail.

tjwalker

Don't get tunnel vision on fuel. Your problem MAY be fuel. It MAY be spark.

You need a strong, blue snapping spark (test for it) and you need 31 psi of pressure.

Which of these are you lacking?

Test for spark. If that is good (and ONLY if), try a shot of starting fluid. If the engine starts and runs for a few seconds, you have confirmed a "fuel delivery problem".

freegdr

clear things up no start or no turn over?

doinwork34

no start. It turns over nice and strong...

Also, the only reason I am focused on fuel is that while for the week that it did work it was completely fine, starting better than I have ever seen it. So Im assuming that since the fuel pump is only making TWO small thumping noises with no buzzing sound now, that it would be a good place to start.

tjwalker

This. Neither of these things takes long and will help you isolate the problem.