Anyone have experience with a failing Walbro fuel pump?

2years on my walbro no issues.

i reused the oem fuel sock, don't run my tank below 1/4, but i did burst my fuel lines as they were old. what a pain to replace.

walbro's need fuel for cooling so if you're running ur tank super low, you could be causing it to overheat.

Thanks for the feedback. The tank is just below 1/2 full, so I don't think that's the problem. I just drove it around a half-hour ago until it warmed up to see if I could pinpoint things a little better. Again, once it warmed up the engine stuttered while accelerating over ~3000-3500 rpms. A friend suggested it may be the MAF, are these symptoms consistent with a failing MAF?

I could still hear the fuel pump, both from the inside of the car and on the outside, next to the filler cap. It sound like a hair dryer on low speed....

my first walbro instal was bad and the sock fell off, my pump swallow a bit of crap from the tank and seized.

I was able to run it backward in fuel and have it spit the crap back out. I tested it and it was good, so I reinstalled it and it worked fine. I also upgraded the power feed from the battery directly to the fuel pump and regrounded it. If it helps. Of course good cold plugs and a clean fuel filter are a given.

test the ground on the maf, make sure the maf plug is on tight, and u could give the maf element a light cleaning with some electronic parts cleaner.

i had my walbro for seven years no problems, i would definately check the maf, fuel pressure regulator

I'm still having the same issues. The car runs great until things warm up, then the fuel pump starts to sound like a hair dryer on low speed, both inside and outside the car. I cleaned the maf (it was spotless to begin with) and checked the connections, replaced the fuel filter, and the ignition system is all brand new. Where's the fuel pressure regulator? How do I check it?

I emailed Walbro for some advise. I've copied their reply and our subsequent "conversation" below for your reading pleasure. Seems they know nothing about Walbro fuel pumps in GTI-R's....

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SUBJECT: Need technical support

Hello,

I purchased and installed a Walbro 255 lph in-tank fuel pump (model # GSS-341) into my 1993 Nissan Pulsar GTI-R (Japanese import). Everything was good for about 4-5 days, then I started to have similar hesitation problems while accelerating the car as I had when the original fuel pump was failing. I can also now HEAR the pump whining in the tank, whereas before I never noticed a sound. Can you tell me if the new pump is failing, or are these symptoms of something different, such as a weak power / ground connection, or plugged fuel filter? I'm replacing the filter just to rule it out, but I'd like to know whether I've installed a faulty Walbro fuel pump or not.

Thank-you for your assistance,

Tyler *******
Winnipeg, MB, Canada

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SUBJECT: Re: Need technical support

Tyler,

Your Nissan Pulsar is an application that we do not endorse the use of our pumps in; it is a vehicle that our application engineering department has not looked at. I don’t know if this is a module assembly application or open hanger assembly…don’t know anything about it I’m afraid.

Depending on the noise level, it certainly could be an indication of a problem but I’ve no way to diagnose it. I recommend that you contact your place of purchase to see if they’ve done similar work with other Pulsars.

Again, this is not a vehicle we authorize the use of our stock replacement or high performance fuel pumps in.

I’m sorry I can’t help you.

Regards,

Diana Hutchinson
TI Automotive Aftermarket
630 Columbia Street
Caro, MI 48723

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SUBJECT: Re: Re: Need technical support

Diana,

Thank-you for your reply. I can tell you that most individuals in the Pulsar GTI-R community around the world use your Walbro GSS-341 fuel pump as a replacement for the stock pump in their vehicles, and it is highly recommended and regarded by these high-performance tuners. For the most part I heard nothing but solid endorsements from many dozens of people regarding the Walbro fuel pump. You may not endorse the use of your pumps in the Pulsar GTI-R, but you must endorse it in many other Nissan vehicles that utilize both the same engine and fueling set-ups, such as the Nissan NX2000, 180SX, and Silvia.

I'm not asking for a replacement pump, I would simply like to know if I need to buy a new one. I've replaced the fuel filter and cleaned my Mass Air-fuel sensor, and am still getting the same issues. The fuel pump in quiet when I start the car and remains so until the engine warms up. The fuel pump then becomes very noisy. I would describe it as a hair-dryer on low speed. If I'm standing outside of the car near the fuel tank, the pump is actually drowning out the sound of the engine. I've asked for advise the from the Pulsar community (online forums) regarding the problem that I'm dealing with, but it seems no one has had this problem before.

Any information regarding my problem would be GREATLY appreciated. Thanks again.

Tyler

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SUBJECT: Re: Re: Re: Need technical support

Tyler,

I’ve talked to engineering and it sounds like a hot fuel situation but we don’t know what’s causing it. Without knowing the cause, you might have the same problem with a new pump.

All I’ve got…

Regards,

Diana Hutchinson

If it starts to make noise, and you shut the car off for say a minute. fire it back up the noise persists?

Just curious to see if you've tested the voltage on ground and power on the pump cold , hot?

Is it possible the pump is vibrating around in the plastic pump holder? maybe the zip ties have broken loose? I put that rubber sleeve that comes with the walbro kit on my pump, did you?

the pump will also sound louder if the sock fall off. it would also swallow small debris which would cause a bad sounding grind in the inner gears of the pump. Have you tested your return lines to make sure they work? Maybe your forcing the pump on clog lines? I ran high pressure air in my lines to test their flow when I installed my pump and to make sure they were free of debris.

0.02$ worth looking at.

For anyone interested, just an update to say that..... my fuel pump problem went away. Very strange, I know. Basically I was about to pull it all apart and re-check the hoses / connections / sock filter / wiring, and decided to drive it around one more time to get the "noisy fuel pump" symptoms again, then shut the car off and re-start it as Nick had suggested for more troubleshooting data. Luckily for me, I couldn't reproduce the problem. I've now driven the R for extended periods for the last 4 days with no issues, the car accelerates well and feels like it did before this all began.

My theory is that the fuel lines were gunked up behind the fuel filter (the crud that oozed out of the old filter when I removed it was seriously sludgy), and it took a few drives to push the blockage into the fuel filter. I may go ahead and change the filter again, just to clear things up more (in hindsight, I should've run the pump for a few seconds before putting the filter on).

Thanks for everyone's help.

I am actually having the exact same situation as yourself... only my pump is still very quiet and I only hear it on the prime when I turn the key on(Normal). I myself had a little hesitation and it seemed as though it was running lean under load. Exhaust was hotter than normal, and smelled lean ect. Since it has been duely noted on how bad Gti-r's are for fuel pumps, I thought I was hitting the nail on the head and went out and got the same gss-341 pump. Everything was hunky dory for the first few days as well, then I noticed it coming back intermittantly. Not as bad and still on the whole runs better, but i can associate it with being more aggressive when not at operating temp, rather than when hot( although still happening at oper.temp). The Install went very well and the old sock is positioned almost exactly as the factory one, and it is definetely not moving around in the casing.(I will try and ad an image of my setup).My fuel tank is spotless so there is certainly not a debris issue.I notice it mostly happens when lower on fuel, usually around a quarter tank, but it has happened with more than half a tank(when the pump is fully submerged) I also have replaced the fuel filter, spark plugs( ngk copper BKR7's)and set the ignition timing, attempting to solve the issue. all made improvements but not for that issue specifically. I am going to do cap/rotor and wires, and graph the o2(changed 2 months ago to pass smog test) to make sure it is still working correctly. I may try and graph the tps to see if it has any voltage spikes, or even just put a fuel pressure guage on it, and drive it to see if the new pump IS acting up. Let me know if your symptoms return at all. I have had almost week long spurts as well where it runs well, and I think it has worked itself out... But then it happened again....... The guy at the performance shop where I picked it up specifically told me "NO WARRANTY" on the part. Probably because it is an electrical part, but still makes me wonder now about these pumps.

what u actually gotta do is trim the notch on the plastic pump casing visible on the bottom of your 2nd picture. so it can snap in lower on the piece thats mounted to the tank. the sock doesn't actually go as far down as the stock setup. in any case, a surge tank fixes the prob.

how much to do take off? A centimeter, inch? Also, what is a surge tank, can you elaborate. Thanx

As for my hesitation issue... it ended up being a restrictive cat converter causing my issues. I removed the stock cat and egt sensor and installed a high flow universal cat in which I modified to accept the sensor by drilling a hole in the pipe where the cat exits and welding a nut on and re threading the egt in. Worked like a charm. Engine vacuum was restored and power is back to normal, no more choking out intermittantly. There is quite a noticable difference in the amount of exhaust coming out the tail pipe, and exhaust seems much throatier(if thats even a word,lol). Will see how it acts now when I get lower on fuel and see if I still need to modify my fuel pump housing to sit even lower still. I am pretty sure that the cat was my main issue all along, so we will see...

Glad to hear you've worked out the issue. My R's been running fine since my problem dissapeared, but if (and when) it comes back I'll definately look closely at the cat. Cheers.