i have no pressure to the fuel rail when the key is on but i do when the vehicle is running is this normal?

 

What year is your cherokee? It would be much easier if you guys would fill in the infos fully.
Do you hear the FP turning when you switch to ignition on (engine off)?

 

i filled the info in and now it doesnt show lol i dont understand why its gotta be mean to me its a 1990 and all i know is it has zero pressure in the on position but it does have pressure when the vehicle is running

 

Ok, you're a Renix brother
What you have to do is get someone switch the key to ignition ON and get your ear to the open tank filling to hear the pump. It should turn for approx. four seconds, if it doesn't wait a few seconds (take pauses in the switching) in ignition OFF to reset the timer.

 

ok but what i dont understand is even if i leave the key on for 5 minutes there never is fuel pressure and it takes a good 10 or more seconds of cranking before it will start and then i have other issues you might know something about after it starts it idles fine when im driving if i barely put my foot on the gas it goes like crazy but if i push any harder it shakes and shutters like its missing and everything tuneup wise is new and if i let back off the the very beginning of the peddle it will accelerate from there im so stumped on this thing

 

You are not listening to me. Do what i told you. I am diagnosing the problem and already have an idea. The pump will turn only for four seconds or less in ignition on but will run continuously when cranking. I understand you are stressed but don't let me repeat things. I am going to tell you the fix as soon i have the asked informations, beleive me i know what i'm doing.

 

ok im a mechanic but im new to the jeep thing and i have never heard of that but i woke up the whole house and we went and check and all it does is buzz for MAYBE a whole second

 

and if i turn it off and back on it does exactly the same thing every time?

 

Did you take pauses between switching? I mean wait 10 seconds in ignition OFF before re-switching to on.

 

ok i was unsure how long to pause so i did it again (roommate very unhappy) too bad haha. and it gets ever so slightly longer every time up till a good 2 and half seconds it took 4 pauses to get it that long

 

Ok, do you want the quick fix or the serious one?

 

both would help its my only vehicle at the moment other that my ford on 38s and not so good on gas so i would like both and i hope one is NOT replacing the pump

 

Ah, another question before i give you the fix: after you did the switching thing about 10 12 times, what is coming out the nozzle on the rail? Air, air+fuel or fuel?

 

air fuel mix kinda spittyat first then it wil spray hard and stop and then you pause and its less air more fuel every time not quite 10 times 6-8ish

 

Fantic - Allow me to hijack this thread while you wait for an answer to your question. I just recently dropped the tank to swap out the fuel press reg/filter, and things are running smoother now. However, just yesterday (5 days after replacing press reg) I noticed that when I tried starting after a long day at work...it didn't start on the first time, it took a couple of times to start. I then stopped at the grocery store...only a 10 min inside, and when I went to start, it started right away. Now, this morning it wouldn't start again until a couple of tries. My guess is that I'm loosing fuel pressure over a long period of time. Like I said, pressure regulator is brand new and no leaks anywhere. What I mean by a couple of times is that, on the first turn of key...no start, then off and when I try again...it does start.