New fuel pump and 4 regulators...still high fuel pressure?!?!?! - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > WJ Grand Cherokee Forum > New fuel pump and 4 regulators...still high fuel pressure?!?!?!

The Cure for your Tie Rod Roll!FS: Wrangler RGB Multicolor Fog Light LEDs: Awesome EffectIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed Line

Reply
Unread 05-19-2015, 07:45 PM   #1
Foxfleet
Registered User
 
Join Date: Dec 2007
Location: Cincinnati
Posts: 14
New fuel pump and 4 regulators...still high fuel pressure?!?!?!

2002 Grand Cherokee Laredo 4WD, 4.0-6 cylinder

Short version-

Low fuel pressure leads to replacing fuel regulator 3 times (on 4th now) and fuel pump once in between regulator 2 and 3. Now have high fuel pressure at idle (60-72psi) and regulator squealing. 52psi without motor running. Injectors are good.

Long version-

So, here's the story...Had a problem with long starts. I went through the injectors (was the culprit a couple years ago) and found nothing. Fuel pressure bleeding off so, I figure it might be time to swap the regulator(autozone special). Still long starts. Find another ever-so-slightly leaking injector. Replace it and all of the seals. A month goes by and everything is fine. Leaving dinner one night and super long crank before start (about 8 secs). Drive home and it's stuttering just a little coming off stop signs and lights. A few days later, my starts are super long and it's taking multiple tries to get it started. Finally had enough and start tearing into things. Fuel pressure gauge says 30psi running and immediate bleed off to 0 once the key is turned off. Injectors are good and new (checked again anyway, no leaks), regulator is good and new so, I replace the fuel pump (autozone, Delphi). Still low pressure. Swap in new regulator (from O'Rielly). Pressure holds 50+psi without the motor running, bounces between 60-70psi at idle...too high...but it's running and that makes me happy. Things are fine for about a day before regulator starts squealing...loudly. That regulator lasted 3 days total before it started dropping pressure to 10psi immediately after shutdown and crank times are getting longer, still 60-70psi at idle...too high. Swapped out for Mopar regulator...it holds 52psi without the motor running and 62psi at idle. Again, that's higher than it should be but, it's running and I have to get to work. Now, 3 days later, it still holds 52psi with the motor off but is now bouncing between 60-72psi at idle and the regulator is squealing again (not nearly as loud as the previous one but still noticeable).

Now, my question for the Knowledge Gods of the Jeep Forum...

What else should I be looking for? What do I need to replace or test? What am I missing?

Thanks in advance.

Foxfleet is offline   Reply With Quote Quick reply to this message
Unread 05-20-2015, 06:52 PM   #2
Foxfleet
Registered User
 
Join Date: Dec 2007
Location: Cincinnati
Posts: 14
Bump. Really need some help. Only vehicle and an hour drive to work everyday.
Foxfleet is offline   Reply With Quote Quick reply to this message
Unread 05-20-2015, 09:02 PM   #3
buddyguy
Registered User
2002 WJ 
 
Join Date: Oct 2014
Location: Whistler, BC
Posts: 4
Interesting... First I'll say my advice is worth what you've paid for it; I don't know much about the newer 4.0s, but...

I'm going to guess it is something other than your pressure regulator or pump since you've burned through 4 regulators by now. I'm not sure if the regulator is controlled by vacuum or electronics but an incorrect input there could be causing it to burn up prematurely. Do you have any other drivability issues? Do you have a wandering idle? Something like a bad throttle position sensor could potentially be telling the injectors to do one thing while the regulator another and causing it to burn up the regulator.

Hopefully someone wiser than myself will chime in now...

BUMP
buddyguy is offline   Reply With Quote Quick reply to this message
Unread 05-20-2015, 09:14 PM   #4
bradywgn71
Web Wheeler
 
bradywgn71's Avatar
2002 WJ 
 
Join Date: Apr 2011
Location: Tucson, Arizona
Posts: 1,149
Maybe there's a restriction in the fuel return line. Have you checked there? A restriction in the return line will not allow the excess pressure to return to the tank. And by regulator, do you mean fuel filter? That's where the regulator is housed and there's nothing vacuum or electrically related to it. It's just spring pressure.
__________________
2002 WJ Overland - 4.7HO - 231tc - 6" Clayton - 285/75-16 Cooper STT - ProComp 5129 wheels - Kevin's Offroad Belly Skid and Rock Sliders - JKS Track Bar and Disconnects - ProtoFab bumpers
bradywgn71 is offline   Reply With Quote Quick reply to this message
Unread 05-21-2015, 06:49 AM   #5
Foxfleet
Registered User
 
Join Date: Dec 2007
Location: Cincinnati
Posts: 14
Thanks for the replies...And, yeah, filter/regulator. Haven't checked the fuel return line yet...didn't think of it. No other running issues so far...just squeals. The squealing seems to quiet down a bit when I'm hard on the gas but I bet that's just because the motor is requiring more pressure. Does anyone know what kind of pressure the fuel pump is supposed to be putting out? Maybe the pump is too active and burning up the regulator? Do you think the pump might be getting too much power?
Foxfleet is offline   Reply With Quote Quick reply to this message
Unread 05-21-2015, 08:12 AM   #6
thecause17
Registered User
2004 WJ 
 
Join Date: May 2015
Location: Smyrna, Delaware
Posts: 233
Quote:
Originally Posted by bradywgn71 View Post
Maybe there's a restriction in the fuel return line. Have you checked there? A restriction in the return line will not allow the excess pressure to return to the tank. And by regulator, do you mean fuel filter? That's where the regulator is housed and there's nothing vacuum or electrically related to it. It's just spring pressure.

I agree, I think it might be possible that your original problem was the regulator, but when you were working on the injectors, something foreign could've gotten into the rail. I'd pull the fuel rail out and make sure it's clear. Hopefully if something did get in there it's still in the rail, not somewhere in the return line between there and the tank.
__________________
'04 Inferno Red Columbia Edition WJ 4.7HO QT-II
thecause17 is offline   Reply With Quote Quick reply to this message
Unread 05-22-2015, 09:56 AM   #7
buddyguy
Registered User
2002 WJ 
 
Join Date: Oct 2014
Location: Whistler, BC
Posts: 4
I wouldn't worry about the pump for now. It is the regulator's job to return undemanded fuel to the tank; a bad pump is only bad when it doesn't supply enough fuel. I'm with bradywgn that there could be a restriction in the return line (possibly from something foreign getting into the rail while cleaning the injectors as thecause mentioned). If the FPR squealing goes away under WOT conditions then this supports that hypothesis. The FPR will be supplying more fuel at low throttle conditions then is demanded or able to be returned to the tank and will cause the FPR to squeal and burn up...
buddyguy is offline   Reply With Quote Quick reply to this message
Unread 05-22-2015, 05:39 PM   #8
Foxfleet
Registered User
 
Join Date: Dec 2007
Location: Cincinnati
Posts: 14
Do you think the obstruction would be in the fuel rail or the return fuel line from the regulator?
Foxfleet is offline   Reply With Quote Quick reply to this message
Unread 05-23-2015, 02:06 AM   #9
bradywgn71
Web Wheeler
 
bradywgn71's Avatar
2002 WJ 
 
Join Date: Apr 2011
Location: Tucson, Arizona
Posts: 1,149
From regulator to tank return, anywhere in between. Maybe a pinched line when the tank was re-installed? Lines hooked up correctly?
__________________
2002 WJ Overland - 4.7HO - 231tc - 6" Clayton - 285/75-16 Cooper STT - ProComp 5129 wheels - Kevin's Offroad Belly Skid and Rock Sliders - JKS Track Bar and Disconnects - ProtoFab bumpers
bradywgn71 is offline   Reply With Quote Quick reply to this message
Unread 05-27-2015, 08:18 AM   #10
Foxfleet
Registered User
 
Join Date: Dec 2007
Location: Cincinnati
Posts: 14
Thanks...Will have a look this weekend. Any possibility that the connection at the regulator could cause the problem? It has that goofy built in removal tool on it. It's kinda rusted up a little and was a mother to get off the first time...think that could be part of the issue? And would it be a bad idea if I replaced that line with some regular fuel hose and a couple hose clamps?
Foxfleet is offline   Reply With Quote Quick reply to this message
Unread 05-28-2015, 11:06 AM   #11
bradywgn71
Web Wheeler
 
bradywgn71's Avatar
2002 WJ 
 
Join Date: Apr 2011
Location: Tucson, Arizona
Posts: 1,149
Fuel in the return isn't under pressure so I don't see why that wouldn't work.
__________________
2002 WJ Overland - 4.7HO - 231tc - 6" Clayton - 285/75-16 Cooper STT - ProComp 5129 wheels - Kevin's Offroad Belly Skid and Rock Sliders - JKS Track Bar and Disconnects - ProtoFab bumpers
bradywgn71 is offline   Reply With Quote Quick reply to this message
Unread 06-28-2015, 02:54 PM   #12
Foxfleet
Registered User
 
Join Date: Dec 2007
Location: Cincinnati
Posts: 14
So, new-ish symptom...the pressure is still running high but not causing any other issues that I can tell. However, the filter/regulator only squeals when it's a little chilly outside. If it's warm, it makes no noise whatsoever. But it was in the low 60's the other morning and it starts squealing again. I haven't been able to find any kind of obstruction and can't think of anything else to check...I can't afford to just start replacing everything piece by piece.
Foxfleet is offline   Reply With Quote Quick reply to this message
Unread 06-28-2015, 04:04 PM   #13
IOwnCalculus
Registered User
2003 WJ 
 
Join Date: Sep 2014
Location: Mesa, AZ
Posts: 37
Isn't "noisy filter/regulator" a common thing with a lot of the aftermarket pieces? Seems like a lot of them use a poor design that vibrates.
IOwnCalculus is offline   Reply With Quote Quick reply to this message
Unread 06-28-2015, 04:25 PM   #14
doityourselfMM
Senior Member
 
doityourselfMM's Avatar
1999 WJ 
 
Join Date: Dec 2010
Location: manassas, va
Posts: 960
Can you 'open' the return line just beyond the fuel rail, and check for return volume? If it looks OK, then try the same thing back at the regulator.

Just a thought to eliminate return restriction.
doityourselfMM is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.