Is my fuel pump going out?
#16
Ok. A little update. Did a pressure test and results are quite interesting. So with the car idling and the vacuum line to the regulator hooked up I got 29psi. With the line out, I still got 29psi. When I pinched the return line pressure just dropped to like 5psi. So there is for sure some **** going on. And when I shut the car off fuel pressure just dropped to zero and with key on it's still zero.
Tested with 2 different gauges btw.
Tested with 2 different gauges btw.
#18
Another little observation today. Intermittently today the car had that lack of power issue. Its gotten better since a few days ago, i am down to about 3/4 of the tank and i think that might be related. What i noticed is that when i am accelerating from a complete stop, normally not jamming the accelerator the truck feels very torque just until it hits about 2.500rpm and then it almost hits a wall i can even hear the engine sound change. Its like someone is blocking the intake and its lacking power. Same happend when getting on the highway too. I would get on the gas and it feel pretty good for a few seconds and then it just looses power.
#19
Another little observation today. Intermittently today the car had that lack of power issue. Its gotten better since a few days ago, i am down to about 3/4 of the tank and i think that might be related. What i noticed is that when i am accelerating from a complete stop, normally not jamming the accelerator the truck feels very torque just until it hits about 2.500rpm and then it almost hits a wall i can even hear the engine sound change. Its like someone is blocking the intake and its lacking power. Same happend when getting on the highway too. I would get on the gas and it feel pretty good for a few seconds and then it just looses power.
#20
CF Veteran
Joined: Nov 2010
Posts: 5,817
Likes: 105
From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
Ok. A little update. Did a pressure test and results are quite interesting. So with the car idling and the vacuum line to the regulator hooked up I got 29psi. With the line out, I still got 29psi. When I pinched the return line pressure just dropped to like 5psi. So there is for sure some **** going on. And when I shut the car off fuel pressure just dropped to zero and with key on it's still zero.
Tested with 2 different gauges btw.
Tested with 2 different gauges btw.
If this line checks out, replace the fuel pressure regulator.
#21
I have a brand new fuel pressure regulator, cat is brand new magnaflow cat. All the vacuum lines are brand new. Vacuum line has good suction.
#24
Nope, adjusted the cable and it shifts fine, it's not the shifting that's causing it. Why no one thinks that my fuel pressure test is obviously showing a potential issue? Or am I totally wrong here?
#30
I have factory service manual and access to all data. Both say 39psi with vacuum line disconnected and 31 with it connected. And when pinching the return line pressure should shoot up to 95psi. Mine stays at 29psi with or without vacuum line and when pinching the line it goes down instead of up.