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Writeup: First Gen Walbro 255 Install FWIW


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Well, I promised a write up, this isn't exactly worthy due to it's lack of complexity but here goes...


There are several Walbro 255 pumps with different alignments and such.

the P/N that works for us is:  F20000169

Mine came with an install kit from TRE Performance: 400-1016


I paid $87.00 for mine off Ebay, which was the best price I found.


Everything I needed was in the kit when it came plus a few extras, the parts I used were the plug adapter harness, the rubber grommet thing for the bottom, filter sock, and high pressure hose and hose clamps.


I'm not going to get into dropping the tank and re-installing, or even extracting the pump assembly from the tank aside from 2 things.


1) of the 3 lines in front of the tank, only remove the pressure and return, easily identified with quick connects at/by the filter. The line that is just coupled with rubber tube goes to the canister and passes right over the tank without connecting to it.


2) when re-installing the pump assembly watch tapping the lock ring, it's a bit smaller than it really could be and it has a tendency to unseat in one of the 3 places just before it's finally tight.


Okay, now my pump was already replaced with a Bosch pump, and there was a wiring adapter there but I ran the new one with the kit anyway. These comparison pictures are of the Bosch, which was sold as a direct replacement.

Here's the Bosch still on the pump assembly, also curious to see what you guys theorize that piece of machinery in the background is:




Here's a couple shots of both pumps side by side:





I said it was an easy swap, they're the same form factor.


Here's the Walbro with the rubber grommet doodle they supplied, good fit on the bottom of our assembly:





The rest is just as obvious, cut the supplied hose and couple it to where the pulse dampener is attached. It came with 2 clamps so I pulled some out of a drawer and put 2 more on just for luck. To look at everything the pulse dampener could be utilized, but it's not exactly the most secure connection on that thing so the hose seemed like a better bet.




And here's a shot of the jumper plug thing that plugged right in to the car's existing fuel pump plug on one end and the Walbro on the other, the Bosch had the same thing:




Not shown is my fuel pressure, the cheap Chinese adjustable regulator was incapable of lowering the pressure below 100 lbs, so I stuck a stock rail back on it for now, I may get a nice regulator for it in the near future.

With the stock L67 regulator my idle pressure at full vacuum is 47, where factory was about 35 in my car before, and WOT no vacuum pressure is 52 where factory in my car was 47.


Idle Pressure:

Stock: 35  Walbro 255: 47


WOT Pressure:

Stock: 47 Walbro 255: 52


Walbro P/N: F20000169

Install kit: 400-1016

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You made a mistake in using those clamps.  At least you have double-clamped the hose--but even still you could have problems.  Those clamps are cheap and gruesome.  Ideally, you'd have used proper fuel-injection clamps.  The "good" clamps are readily available at any auto-parts store, and they're not terribly expensive.


The clamps you used are going to end-up doing this to the new hose:



You can also see my recommendation for replacement clamps in the photo--I get mine from NAPA, but they're available "everywhere".  No slots to allow the hose to cold-flow through, the edges are rolled so they don't cut into the hose, and they're more "smooth" inside so again they don't promote hose damage.  Far superior to ordinary worm-gear clamps.

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my tank is kind of crustified piece of crap so I would like to replace it next year anyway. those clamps are much nicer so I will switch over to those now that I see them, either way it's got to be better than that pulse dampener

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  • 3 years later...

Update: Make certain you're getting a walbro, these years later I realize my pump didn't actually have any identification on it and may indeed have been a knockoff. Knockoffs do happen.

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Thanks Imp for posting about the lines for the tank, I'm doing this job soon so that's good to know.

Been sicky icky so haven't sent out that HUD cover yet,  will do sometime next week.  Also, kinda forgot about ya til now.

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Knockoff Walbros are a HUGE problem, especially on eBay. I recommend buying from an authorized vendor like Summit or something. I saw the same thing when I was looking for the AEM pump in my Regal.  Like magnitudes cheaper from some eBay vendors.. if it seems like it's too good to be true, it probably is.

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  • 3 years later...

Bumping an old thread, I know, but does anybody know if this pump fits or is an upgrade for 1.5 gen MC/ Lumi? I'm looking to upgrade mine in the Z34 to handle the LS4.

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So I did check that, via RockAuto anyway, and the part numbers cover the 1st gens and up to '96 MC/ Lumi. I can't think of anything that would differ between 95/96 MC and Lumi vs. 97+. That's why I'm unsure and thought I'd ask.

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  • 2 months later...

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