Anyone had a walboro go bad, bouncing pressure. - 3000GT/Stealth International Message Center

sublime_whatigo · 07-23-2008, 01:33 PM

I have a hotwired walboro 255 and aem regulator and a autometer gauge.

I noticed the fuel pump sounded a little louder than before with kind of a bouncing whine, checked out the gauge and its bouncing at a fast pace between 34-38psi at idle. It was running plenty rich at WOT but Im trying to avoid making pulls with the logger to figure this out just in case. Thanks for any help.

lawdogg · 07-24-2008, 05:59 AM

Are you sure it's the pump and not the AEM FPR?

Have you tried swapping a stock FPR back in?

SkortchGT · 07-24-2008, 06:12 AM

Same exact thing happened to me. I also have a hotwired Walbro. After the AEM FPR & fuel rail loop install, the pump is loud as hell. Base fuel pressure is set to stock (43.5 with vac line off).

My base pressure at idle (with vac line on) does the same thing as you described, bounces back and forth between 34-38psi. I can't monitor the pressure while driving since it's an underhood gauge, however I've done numerous pulls up to 18psi to redline and my tune is perfect. 11.6 AFR (AEM wideband) to redline. The car is running great despite this weird problem. I have no unusual rich or lean conditions. I've verified this on my WB02 as well as my datalogger.

I'm not sure why this happens. I've also noticed at first the AEM FPR would hold fuel pressure after the car was shut off, and now it doesn't. I've talked to a few other people running these and they said the exact same thing. First it would hold pressure after the car has been shut off, then for some reason it would start to not hold pressure.

Nothing to bad about this, just takes an extra crank of two of the motor to start up.

valmes · 07-24-2008, 06:59 AM

Check your wires(ones that go to the fuel pump)... if they are getting too hot... you might consider checking everything out and replacing your pump.

Mine just burned inside the fuel tank... melted fuses and wires...

PS: I think it should be a rule of thumb to replace your "upgraded/hotwired" fuel pump once in a while... wouldn't recommend running the same pump for more than a year...

SkortchGT · 07-24-2008, 07:34 AM

Quote:

Originally Posted by valmes

Check your wires(ones that go to the fuel pump)... if they are getting too hot... you might consider checking everything out and replacing your pump.

Mine just burned inside the fuel tank... melted fuses and wires...

PS: I think it should be a rule of thumb to replace your "upgraded/hotwired" fuel pump once in a while... wouldn't recommend running the same pump for more than a year...

That replacement schedule seems a little extreme to me. There are tons of people running hotwired Walbro & Supra (Denso) pumps without any of the problems you mentioned.

It sounds like you may have other electrical problems.

sublime_whatigo · 07-24-2008, 09:46 AM

Quote:

Originally Posted by SkortchGT

Same exact thing happened to me. I also have a hotwired Walbro. After the AEM FPR & fuel rail loop install, the pump is loud as hell. Base fuel pressure is set to stock (43.5 with vac line off).

My base pressure at idle (with vac line on) does the same thing as you described, bounces back and forth between 34-38psi. I can't monitor the pressure while driving since it's an underhood gauge, however I've done numerous pulls up to 18psi to redline and my tune is perfect. 11.6 AFR (AEM wideband) to redline. The car is running great despite this weird problem. I have no unusual rich or lean conditions. I've verified this on my WB02 as well as my datalogger.

I'm not sure why this happens. I've also noticed at first the AEM FPR would hold fuel pressure after the car was shut off, and now it doesn't. I've talked to a few other people running these and they said the exact same thing. First it would hold pressure after the car has been shut off, then for some reason it would start to not hold pressure.

Nothing to bad about this, just takes an extra crank of two of the motor to start up.

Ya Im familiar with the aem fpr not holding pressure anymore, but what worries me is why the fuel pump is much louder and makes some funny sounds, guess ill have to check it out to be safe. Thanks.

alex10superman · 07-24-2008, 10:23 AM

From what I've read, walbro's are just louder and they always have been. which I guess is why some people prefer the denso supra pump since its OEM quiet.

sublime_whatigo · 07-24-2008, 12:38 PM

Quote:

Originally Posted by alex10superman

From what I've read, walbro's are just louder and they always have been. which I guess is why some people prefer the denso supra pump since its OEM quiet.

Ya I understand Ive had the pump in for over 3 years, its just suddendly got louder.

Anyways I made some pulls and checked everything over, it seems to be fine, must just be that regulator not keeping a constant pressure and making the pump work harder.

lawdogg · 07-24-2008, 12:42 PM

I just ordered the same AEM AFPR setup, so I guess now I know what to expect.

valmes · 07-25-2008, 01:51 AM

Quote:

Originally Posted by SkortchGT

That replacement schedule seems a little extreme to me. There are tons of people running hotwired Walbro & Supra (Denso) pumps without any of the problems you mentioned.

It sounds like you may have other electrical problems.

I know, but I prefer to be safe than sorry... I've seen many walbros fail in 2-3 years.
... and when you know how most of the people "hotwire" their pumps (using stock, mostly "tired" wiring, to supply higher voltage to the pump) there is no reason not to replace it, when it suddenly starts acting weird. Usually it gets louder, but you won't see any changes if you inspect it visually... until it fails completely.

PS: Even Weldon pumps get changed every season

07-23-2008, 01:33 PM	#1 (permalink)
sublime_whatigo Hates Gravel Join Date: Sep 2002 Location: G.R. Michigan Drives: reliable car (nissan Trader Rating: (24)	Anyone had a walboro go bad, bouncing pressure. I have a hotwired walboro 255 and aem regulator and a autometer gauge. I noticed the fuel pump sounded a little louder than before with kind of a bouncing whine, checked out the gauge and its bouncing at a fast pace between 34-38psi at idle. It was running plenty rich at WOT but Im trying to avoid making pulls with the logger to figure this out just in case. Thanks for any help. __________________ 92 3000GT VR4 Black Wheel Mafia - Member 002 Matt

07-24-2008, 05:59 AM	#2 (permalink)
lawdogg Here for the tuna. Join Date: Jul 2003 Location: Williamsport, PA Drives: The Speed Limit Trader Rating: (65)	Re: Anyone had a walboro go bad, bouncing pressure. Are you sure it's the pump and not the AEM FPR? Have you tried swapping a stock FPR back in? __________________ 94 VR-4: 11.8 @ 116, 17psi, pump, 13Ts

07-24-2008, 06:12 AM	#3 (permalink)
SkortchGT Warning: I'm an asshole Join Date: Jan 2002 Location: Lehigh Valley, PA Drives: 1992 3000GT VR4 Trader Rating: (10)	Re: Anyone had a walboro go bad, bouncing pressure. Same exact thing happened to me. I also have a hotwired Walbro. After the AEM FPR & fuel rail loop install, the pump is loud as hell. Base fuel pressure is set to stock (43.5 with vac line off). My base pressure at idle (with vac line on) does the same thing as you described, bounces back and forth between 34-38psi. I can't monitor the pressure while driving since it's an underhood gauge, however I've done numerous pulls up to 18psi to redline and my tune is perfect. 11.6 AFR (AEM wideband) to redline. The car is running great despite this weird problem. I have no unusual rich or lean conditions. I've verified this on my WB02 as well as my datalogger. I'm not sure why this happens. I've also noticed at first the AEM FPR would hold fuel pressure after the car was shut off, and now it doesn't. I've talked to a few other people running these and they said the exact same thing. First it would hold pressure after the car has been shut off, then for some reason it would start to not hold pressure. Nothing to bad about this, just takes an extra crank of two of the motor to start up. __________________ 1992 3000GT VR4 --Completely rebuilt 5/06-4/07. Everything new. For a list see: http://www.3si.org/forum/showthread.php?t=372579 --First time on dyno: 364AWHP@16psi with a 10.3AFR (now tuned at 11.4-11.6 with timing control, time for another dyno run soon) --Mods: DR Stage I heads, 3rd gen lifters, TD04L 13Gs, DSM SMICs, PTE 550s, Apexi SAFC, Apexi SITC, Walbro FP, IPO hotwire, Robbeck adapter & AEM FPR, 3SX underhood fuel gauge, 3SX fuel rail loop, DN Y-pipe, HKS SSQ BOV, K&N FIPK, Greddy Profec Spec S, AEM WB02, Autometer C2 boost, egt, oil press & water temp gauges, MSD wires, NGK BCP7ES's, TEIN FLEX coilovers, Maximal performance control arms, solid engine mounts & powdercoating, RPS Streetmax Clutch, RPS Flywheel, NBT Tranny (cryotreated OS, shift forks & rails), updated speedo gear, solid shifter bushings, full 2nd gen brake conversion, 3SX SS brake & clutch lines, Carbotech Panther+ pads in the front & Bob Cats in the rear, 3SX clutch vac delete, EGR delete, vac reduction, Ebay DP, gutted pre cats, Bronze FN01RCs 5Zigen 18x8.5 + 30 offset, Pirelli P-Zeros, engine dress up kit, Bigtyla ground wire kit. --Daily Driver: 98 Malibu, 4cyl, auto

07-24-2008, 06:59 AM	#4 (permalink)
valmes Forum Member Join Date: Feb 2005 Drives: '97 VR-4 Trader Rating: (0)	Re: Anyone had a walboro go bad, bouncing pressure. Check your wires(ones that go to the fuel pump)... if they are getting too hot... you might consider checking everything out and replacing your pump. Mine just burned inside the fuel tank... melted fuses and wires... PS: I think it should be a rule of thumb to replace your "upgraded/hotwired" fuel pump once in a while... wouldn't recommend running the same pump for more than a year... __________________ Engine Calculator 1.2

07-24-2008, 10:23 AM	#7 (permalink)
alex10superman I love my VR-4!!! Join Date: Aug 2006 Location: New Mexico Drives: 1997 3000GT VR-4 Trader Rating: (2)	Re: Anyone had a walboro go bad, bouncing pressure. From what I've read, walbro's are just louder and they always have been. which I guess is why some people prefer the denso supra pump since its OEM quiet. __________________ More Pictures of my car here -> Pics

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07-24-2008, 12:42 PM	#9 (permalink)
lawdogg Here for the tuna. Join Date: Jul 2003 Location: Williamsport, PA Drives: The Speed Limit Trader Rating: (65)	Re: Anyone had a walboro go bad, bouncing pressure. I just ordered the same AEM AFPR setup, so I guess now I know what to expect.