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  #91  
Old November 19th, 2017, 20:54
Intellect Intellect is offline
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New fuel pump, new regulator, still has fuel pressure issue..

Im writing off the pressure as a leaky pressure regulator, the o ring. Since the rail had to be masaged back strait where it sits.

WHO KNOWS


Like i said earlier, maybe the pressure has always bled off and i just didn't know cause the pump was electrically fine and primed it right up.



If ign switch doesn't fix it, hotwire a switch to pump as a primer switch? Lmao

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  #92  
Old November 19th, 2017, 21:06
Intellect Intellect is offline
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New fuel pump, new regulator, still has fuel pressure issue..

Im reading a lot of ignition switch forums... To clear up earliers terms I used...

When i turn key half and the pump delays and check engine light delays, i can still attempt to crank vehicle. (Starter works, flex plate spins etc) it just has no gas because... Well mr pump is late to the party.

I only mention this because the ignition switch posts are all saying people had no crank situations where not even the starter would engage, basiclaly a bad ignition immitates a dead battery, which isnt my case. The plate gets spun, the system just has no fuel.


Id hate to throw money at an ecm/pcm, and radioshack died so i cant just replace caps.

Why oh why mr jeep

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  #93  
Old November 19th, 2017, 21:51
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Ecomike Ecomike is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Every jeep ignition switch I replaced, and many others on this forum, was due to stuff other than the crank starter not running. Usually stuff like dead blower and dead windshield wipers was the part of the Ign switch that died. I have seen them so fried and loose and sloppy, etc, that I have no reason not to believe that it is a contact in the switch or wire that goes to power the ECU that then powers the fuel pump that can be your intermittent problem. You already know the HVAC blower power is dropping out at times.

Warning folks, ignor the first 6 minutes of his video, unless your bored stiff with nothing to do, LOL, the noise finally happens near the end of it. Sounds like a noisy buzzer in the dash, no idea what it is.
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34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #94  
Old November 19th, 2017, 21:53
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Re: New fuel pump, new regulator, still has fuel pressure issue..

There are better online electronic parts sources.

Quote:
Originally Posted by Intellect View Post
Im reading a lot of ignition switch forums... To clear up earliers terms I used...

When i turn key half and the pump delays and check engine light delays, i can still attempt to crank vehicle. (Starter works, flex plate spins etc) it just has no gas because... Well mr pump is late to the party.

I only mention this because the ignition switch posts are all saying people had no crank situations where not even the starter would engage, basiclaly a bad ignition immitates a dead battery, which isnt my case. The plate gets spun, the system just has no fuel.


Id hate to throw money at an ecm/pcm, and radioshack died so i cant just replace caps.

Why oh why mr jeep

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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #95  
Old November 20th, 2017, 05:36
Intellect Intellect is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by Ecomike View Post
Every jeep ignition switch I replaced, and many others on this forum, was due to stuff other than the crank starter not running. Usually stuff like dead blower and dead windshield wipers was the part of the Ign switch that died. I have seen them so fried and loose and sloppy, etc, that I have no reason not to believe that it is a contact in the switch or wire that goes to power the ECU that then powers the fuel pump that can be your intermittent problem. You already know the HVAC blower power is dropping out at times.

Warning folks, ignor the first 6 minutes of his video, unless your bored stiff with nothing to do, LOL, the noise finally happens near the end of it. Sounds like a noisy buzzer in the dash, no idea what it is.
Hmm you only had to say wipers 3 times for me to remember my wipers only work on high.

Or thats a seperate issue, it never bothered me, just MORE food for thought.


Im buying an ignition switch and going from there i guess. Psi keeps dropping to 0 overnight. But if the pump kicked on normally i dont think the psi would be an issue.

A problem thats always been there but gradually has gotten worse over the span of a year sounds electrical. Ah i remember when it was just a double crank. Turn engine over a few seconds. Let off. Try again, vroom! ... Boy do i miss those days about now.

Thank you for all of your help, its been most useful, folks had me chasing cps/tps/iac/map/ etc. Lets just say, all my sensors are in working order. I knew from that point it was fuel related. Than a purchased a gauge kit. And chased the entire fuel bleed off. Never looking back to realise the pump/check engine light thing till 2 ish weeks ago. (I always thought i had crappy lemon pumps, until i just happened to be starring at the check engine area as i cranked cold one day)

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  #96  
Old November 20th, 2017, 08:14
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Wipers, there is solid state timer delay black box right under the kick panel of the dash near the steering column shaft, and of course the column selector multi switch as well. But lets see what all a new switch does first.
While under there inspect all the wiring for any burned or melted connections, connectors. Don't frget to check that rubber vac hose between the MAP and the throttle body. If it is on its last legs, it could cause the code 13.
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #97  
Old November 20th, 2017, 09:22
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Do this:

With engine up to temp with fuel pressure gauge connected. Find the return fuel line where it is rubber and is accessible to clamp with flat blade pliers. Start engine, read gauge, clamp return line. Pressure should jump up to 70>90 psi, turn engine off with line still clamped. If pressure drops fast it will indicate fuel pump check valve. If it stays up or drops a small amount it will indicate regulator or injector leak, if it steadily drops it will be injector.
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  #98  
Old November 20th, 2017, 09:35
Intellect Intellect is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by Ecomike View Post
Wipers, there is solid state timer delay black box right under the kick panel of the dash near the steering column shaft, and of course the column selector multi switch as well. But lets see what all a new switch does first.
While under there inspect all the wiring for any burned or melted connections, connectors. Don't frget to check that rubber vac hose between the MAP and the throttle body. If it is on its last legs, it could cause the code 13.


Ive been under this dash a few times recently. Everythings good. Nothing melted or out of ordinary.


UNRELATED: One time the headlight delay module white wire with black stripe, the rubber got rubbed off the wire and the copper touched metal.. little smoke and check engine light stopped working that entire abs/brake/cel section. BUT. All i did there was run a new wire from delay module to fuse under dash and that fixed it no problem. This wire controls all of the power to that area. Had a tech help walk me through it.


Im doing an ignition switch today and reporting back. $30 autozone with lifetime warranty. So why not.
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  #99  
Old November 20th, 2017, 09:38
Intellect Intellect is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by comanche91 View Post
Do this:

With engine up to temp with fuel pressure gauge connected. Find the return fuel line where it is rubber and is accessible to clamp with flat blade pliers. Start engine, read gauge, clamp return line. Pressure should jump up to 70>90 psi, turn engine off with line still clamped. If pressure drops fast it will indicate fuel pump check valve. If it stays up or drops a small amount it will indicate regulator or injector leak, if it steadily drops it will be injector.
Ill try this, but im at my wits end for the pressure issue. No matter what it hits 0psi eventually. After 4-5 hours.

I figured ill chase the electrical grimlen instead because ahen the pump DOES turn on just fine, and i have my gauge hooked up, a single half turn or two gets it to pressure. So ideally if i solve electrical or whatever makes the pump delay. All ill have to do is half turn the key, wait 3 seconds. Than crank er over. Which is what i do with ALL my vehicles anyway, maybe im crazy but even a healthy system sill last longer if your gentle with her, let the pressure build. Same logic as i let them sit if cold.
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  #100  
Old November 20th, 2017, 09:42
Intellect Intellect is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by comanche91 View Post
Do this:

With engine up to temp with fuel pressure gauge connected. Find the return fuel line where it is rubber and is accessible to clamp with flat blade pliers. Start engine, read gauge, clamp return line. Pressure should jump up to 70>90 psi, turn engine off with line still clamped. If pressure drops fast it will indicate fuel pump check valve. If it stays up or drops a small amount it will indicate regulator or injector leak, if it steadily drops it will be injector.
Ps - even where the return lines "rubber" it is hard plastic underneath. I HAVE clamped off the return line and it still loses pressure. Somewhat slower. But does happen. Probably the rail where the pressure reg sits, BUT once again, its such a sloooow bleed that a single prime gets her where she needs to be. Maybe 2 primes.
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  #101  
Old November 20th, 2017, 09:47
Intellect Intellect is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by comanche91 View Post
Do this:

With engine up to temp with fuel pressure gauge connected. Find the return fuel line where it is rubber and is accessible to clamp with flat blade pliers. Start engine, read gauge, clamp return line. Pressure should jump up to 70>90 psi, turn engine off with line still clamped. If pressure drops fast it will indicate fuel pump check valve. If it stays up or drops a small amount it will indicate regulator or injector leak, if it steadily drops it will be injector.
To recap. 3 new fuel pressure regulators (different brands, even tried 2 junkyard oems), 2 offbrand pumps, a bwd pump and a bosch, 6 injectors, tried a one way check valve (which blew first use). All lines are solid not broken. I got the bleed of minimilized to not hitting zero for 4.5 hours.

Bledd off is inevitable
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  #102  
Old November 20th, 2017, 09:56
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comanche91 comanche91 is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

I have a stroker and am using the 96-99 Mopar 53030778 injectors with an adjustable FPR and run around the same fuel pressures as you do, 49 w/o vac, 39 w. vac. On the MJs there is a section of rubber fuel hose on the right side of the rear axle just before the supply and return lines connect to the hard front lines. I clamp the return line there for pressure tests. Maybe the XJ fuel lines run differently, but there has to be a rubber to hard line transition back there somewhere you can clamp.

My fast pressure drop turned out to be the fuel pump check valve, and the aftermarket inline check valve did the trick. Once my fuel pump dies and gets replaced, I'll ditch the inline check valve. Until then, it's doing fine.
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  #103  
Old November 20th, 2017, 10:20
Intellect Intellect is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Ill try clamping there... Im circling back to the bleed off once i figure electrical. I dont mind waiting for the prime before i start. Mine isnt the pump check valve, i tested it out of the tank.
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  #104  
Old November 20th, 2017, 15:18
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Ecomike Ecomike is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

That is what I recall too, I think mine bleeds off to zero overnight, or after 4-5 hours...but I could not find where I made any notes.

Mine was a 50% pressure drop in 20 minutes earlier this year, cruiser54 said that was good to go,

so I moved on and found the real problem after way too much grief, it was shear pin in the Dizzy drive gear going bad screwing with the timing, very rare and hard to locate unless you knew what to look for. It was not obvious until the pin completely failed.

Quote:
Originally Posted by Intellect View Post
To recap. 3 new fuel pressure regulators (different brands, even tried 2 junkyard oems), 2 offbrand pumps, a bwd pump and a bosch, 6 injectors, tried a one way check valve (which blew first use). All lines are solid not broken. I got the bleed of minimilized to not hitting zero for 4.5 hours.

Bledd off is inevitable
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #105  
Old November 20th, 2017, 16:02
Intellect Intellect is offline
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by Ecomike View Post
That is what I recall too, I think mine bleeds off to zero overnight, or after 4-5 hours...but I could not find where I made any notes.

Mine was a 50% pressure drop in 20 minutes earlier this year, cruiser54 said that was good to go,

so I moved on and found the real problem after way too much grief, it was shear pin in the Dizzy drive gear going bad screwing with the timing, very rare and hard to locate unless you knew what to look for. It was not obvious until the pin completely failed.

That makes me feel better about my bleed off. Maybe i fixed it than. If you could find that note i appreciate it ..

Also, new ignition switch... Pump delay is still there, i just finished up. Thinking of putting my old one back in and putting that $35 elsewhere.
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