I've got a 94 Grand Cherokee with a 4.0 liter. It stalled out the other night and I had to have it towed home. It will barely start and when it does it will bogg down and die within 20-30 seconds. Fuel pump is turning on and creating pressure but it seems quite low. I don't have a fuel pressure tester but I am pretty sure it is not anywhere near the 40 psi mark. I changed the filter but that didn't help. Fuel pump was replaced 2 years ago. could it be the fuel pressure regulator??

 

Ya it could be. But check to see if the fuel pump is getting enough electricity relay. Have you checked the fuel rail? It should spray like a hose if it is getting proper pressure to the motor. Have someone start it and you push the fuel rail pressure release and see if it sprays out or barely drips out

 

Yeah. Barely drips. I have killed my old battery from all of the cranking and need to get it a good charge or buy a new one so it has been difficult to test any electrical stuff.

 

I have a 94 Grand Cherokee with a 4.0 liter. It died the other night while my wife was driving it and I had to have it towed home. It seems like it is fuel related because it will sometimes start for a few seconds but wont stay running. I can here the fuel pump turn on and it primes but the pressure is very low. I don't have a pressure tester so I don't know exactly where the pressure is at but I know that it is way low because gas is barely trickling out when I push on the release valve. The fuel pump was replaced 2 years ago and I replaced the filter after it died. Kind of hoping it was the fuel regulator. Anyone have something similar happen to them? Any ideas?? BTW. Don't suggest the crankshaft position sensor. I have been down that road a few years ago(what a pain in the ***) and finally replaced it after chasing other areas of concern. Thanks

 

take the injectors out they are clogged or corroded. had the same problem working on a blazer once. and if not get new fule filter it probably clogged.

 

Already replaced the fuel filter and the injectors were replaced along with the fuel pump and regulator 2 years ago.

 

till if it was sitting oround for a while or justing cheap *** gas it will clogg it. dont mattter when u replaced it. it could just be beaten on or sitting around with cheap fule. it clogs worse then plus or supream gas.otherwise you need a new distributor or ignotion coild depending on the year just could be getting weak spark and that wll lead to a sputtering problem

 

No man. I just replaced the coil 6 month ago. I have almost no fuel pressure! Thanks for your input but seriously man?

 

check the flow at the filter see if it has pressure and move to next in line till you find the problem (just because you changed them in the past does not mean it is not plugged up again or faulty???) start at the pump work forward??????

 

It ended up being the fuel pump. Second one in 2 years! Maybe wont get an airtex next time! We bipassed the relay and hardwired it and even with it running continuously did not create enough pressure in the fuel line so we figured it was the pump which it was.

 

So I got a new battery and bypassed the realay which ran the fuel pump continuously. Even with it running nonstop, it was only producing a fraction of the PSI that was normal. Replaced the fuel pump and we are back running again. Second fuel pump in 2 years! Airtex may not be the best choice for me next time.

 

yeah airtex pumps are complete junk, it also could have failed if you run it low on fuel a lot