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Walbro 255lph acting up, (noisy, fixed!)


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Hi

There's this 240z l28et with 255 walbro that im looking at, but it has a starvation problem. Idle's fine, but when driven it is rough, boggs down, running lean. It has a secondary pump ( not sure what brand) that feeds the walbro. The seller says that the pump might be bad. I was wondering if i can use the 240z or 280zx fuel pump as the secondary. i can't find the spec for thhose stock pumps, as i read that the carter pump you used is 5psi.

So im wondering if i have to buy that one or some other pump. Would be easier for me to use the fuel pumps that i have around though ( the 240 and 280zx).

thanks

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I thought I would post here and let you guys know that the feeder pump fix worked for me. I am copying it from my post in the Volkswagen forums, so a few things will sound funny.

 

I finally got enough money to repair the issues the car has been having.

 

I reworked the fuel system so that a Carter carburetor pump has taken the place of the Bosch 044. It has an upright configuration that made it hard to retrofit, but I made it work with a very funky fitting that I will get a picture of soon.

 

Then I cut some lines up and spliced in another Walbro pump near the passenger rear shocktower. It is a smaller Walbro(GSL-393) than the one I had before(GSL-392), but still flows enough fuel at 70 psi to make 300 FWHP. I went with Walbro because I found it for cheap on ebay, I was assured that it was brand new and genuine, and I already had the AN fittings for it. There is an inline 35 micron filter between the two pumps, but other than that it is a direct feed.

 

Electrically, I wired them up with seperate 4-pin relays. The walbro has a direct fused line from the battery, and grounds to the ground strap on the trans. The Carter accepts power from the main fuseboard in the trunk. I used the fuel pump output on the megasquirt relay board to trigger both relays so that the fuel pumps will turn off with no engine signal (so I have a relay triggering two relays, haha). Additionally, the Carter's power supply is interrupted with a Ford inertia switch. Brian at BoostEngineering.net gave me one free with my EDIS kit. It is mounted in the front apron and will disconnect power from the pump if there is a jolt (from a crash). I have scraped the swaybar several times and am happy to report that it hasn't prematurely cut off yet. It also makes for a really obscure killswitch when the car is parked somewhere.

 

Other than a leak from one of the fittings that was easily repaired, the startup was perfect. Static fuel pressure is rock solid, with no noises coming from the Walbro. The Carter is a little loud but pretty indistinguishable once the engine's on.

 

So to all the old heads on here ( Pile, raygreenwood) who kept wagging your fingers, you won. It works. I am a believer. Sorry for doubting the necessity; even now if I could get away without a feeder I would have, but here I am. Best of all, the two small pumps in combination use less peak amps than the big Bosch. Symptoms I had before that some relate to fuel temperature (cavitation, boiling) never occurred. It was 100 degrees out today, and the fuel never hiccupped once. Can't wait to do some real tuning on this thing.

 

Took mom out to get lunch. I can tell how much I'm going to love this car by how much she hated it. :twisted:

 

EDIT: here's a picture of the Carter, with the crazy fitting I made from some NPT tubing and a -12 weld-on bung.

 

l_57a294ba8b4e4f018805ed0ec1b1ce17.jpg

 

Also, I was playing with the engine when I got home and the fan sucked in a spark plug wire. Woohoo! One step forward and two back. Need to figure out how to make another, and then secure them to the firewall properly. I'm so happy the fuel system works I'm not even that mad. :lol:

 

EDIT # 2:

For anyone that wants a good deal on this pump, here's the link: 75 bucks with free shipping and install kit. When the link goes bad, the seller's name is djd16. http://cgi.ebay.com/ebaymotors/BMW-E30-E12-E21-M10-M20-M30-New-Walbro-GSL393-Fuel-Pump_W0QQitemZ220440180907QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item33534238ab&_trksid=p3911.c0.m14&_trkparms=65:12|66:2|39:1|72:1205|240:1318#ht_2877wt_1191

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Hi

There's this 240z l28et with 255 walbro that im looking at, but it has a starvation problem. Idle's fine, but when driven it is rough, boggs down, running lean. It has a secondary pump ( not sure what brand) that feeds the walbro. The seller says that the pump might be bad. I was wondering if i can use the 240z or 280zx fuel pump as the secondary. i can't find the spec for thhose stock pumps, as i read that the carter pump you used is 5psi.

So im wondering if i have to buy that one or some other pump. Would be easier for me to use the fuel pumps that i have around though ( the 240 and 280zx).

thanks

 

I would say look for a pump that is good at creating suction from the tank. The Carter sucks very well from the tank, provides a ton of volume, but not much pressure. If your feeder pump is shaped the same as the walbro, I would say that it will not work as well. The two pumps perform entirely different functions. The carter will provide 72 GPM, or for higher output you could look into the Holley pumps (blue, red, black).

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I know this is an old thread, but I'd like to add that the walbro or any fuel injection pump for that matter is a fuel pusher Not a fuel puller

your problems would have been solved quicker and sooner by mounting the injection pump at the rear of the car by the fuel tank which is also the stock location for the pump on any injected car

 

I write this to inform, because reading it concerned me about the walbro pumps, which is what i'm using on my zx turbo

and when mounted properly its a great pump

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From my own experience here I'm beginning to wonder if part of the fuel pump being noisy/acting up issue is what I've been encountering and what I've found jeffp seemed to encounter and has said. Basically from what I've gathered thanks to jeffp is that these old relays and wiring are not up to par to really support aftermarket higher flowing pumps. My issue seems to be that my pump will start to get loud after a little while of driving and the relay begins to get quite warm, to hot and I'll see a drop in fuel pressure. I'm wondering if like with the OP installing a low flow pump which really won't require higher voltage/amperage which then feeds the main pump takes a lot of load off the main pump making it super quiet and also taking strain off the electrical system? I'm almost debating getting a small pump or installing my original 280Z pump before my Bosch and seeing if suddenly the issue of fuel pump whine along with fuel pump relay heat goes away.

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I put an in tank Walbro in my 240Z. Cut the top off an SX tank, the part that holds the pump, and welded it into a Z tank. I also installed the sx in tank sump while at it. It worked great for a couple of years but lately it seems a bit noisy and I am getting some hesitation during hard acceleration. I pulled it out and the screen is very dirty but haven't replaced it yet. I cleaned it but it still looked funky. I have plenty of voltage at the pump. I cut a hole in the floorboard and made a cover so I can replace it easily. I will let you know how it works but some people are not fond of the Wolbro's. I believe Deutchworks makes one also.

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I'm starting to really believe what was said that these pumps are meant to be fuel pushers and not pullers. I'm beginning to wonder if my noisy pump is simply because the way it's mounted is not letting the body be completely fuel filled by gravity. It's still have to pull to fully fill and then push the fuel.

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Switched from walbro to bosch 044 pump.the walbro is really designed to be an in tank pump.I had my pump mounted even with the bottem of my tank with -6 hose earl's push lok hose clamped on at the tank .car is a 1977-the tank has a 3/8 or 10mm hose nipple and I know that works.if i idled the car on a hot day the fuel pressure would drop with the walbro.the bosch is mounted lower with an earl's 80 micron screen filter before it

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Actually I've switched to the Bosch 044 and I'm still having the same issues. Pump getting loud after a while and fuel pressure dropping, but I don't have it mounted even with the bottom of the tank. I mentioned in previous post it's mounted vertically so really it's seeing only about half way up the body of the pump where the tank output is. I'm going to try to mount it horizontally with the bottom of the tank so it will have to not do any pulling to fill the pump and gravity will completely fill it.

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Just for general knowledge, I have 3 walbro's, none very quiet even though they are all "in tank" pumps. One was especially loud so I changed it to a Deutchworks(sp). That pump is so quiet I had to put my ear on the tank to hear it working. The walbro was not the problem so the pump worked fine even though it was noisy. I had a bad fpr.

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  • 5 months later...

Yet another revival!

I'm days away from mounting an sr20 into my 73 and I got a walbro inline,

After reading all this, still not sure if I should get a helper pump like the carter mentioned by the OP, or should I get an entirely different pump??

I plan on using the stock tank since I already had it restored

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Yet another revival! I'm days away from mounting an sr20 into my 73 and I got a walbro inline, After reading all this, still not sure if I should get a helper pump like the carter mentioned by the OP, or should I get an entirely different pump?? I plan on using the stock tank since I already had it restored

There shouldn't be a problem if you mount the pump close to the tank and as low as the bottom of the tank.

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  • 3 months later...

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