Installed a Walbro lift pump

[MFalkinham]

After reading the numerous horror stories about the stock lift pump failing, I decided to install a replacement pump made by Walbro. The Walbros are not as common as some of the other aftermarket lift pumps, but they are cost effective and seem to be well built. The total cost of the parts for my Walbro system worked out to about the same as a FASS system. However, this price also included a spare Walbro pump for me to carry under the rear seat, plus other nice features like the Geno's fuel canister billet cap and some Jeg's fuel gauges.

I designed a custom bracket to be mounted inside of the fender ahead of the drivers side rear tire (where the FASS system would normally mount). This bracket was made of heavy gauge steel angle bracket and then welded to serve two purposes. First, it had to securely hold the Walbro plus a PermaCool fuel filter/separator. Second, it had to protect both of these items from road debris. I designed it so it does not hang lower than the frame, and it has aluminum diamond-plate guards that are removable for service. I also added a small Fram inline fuel filter to serve as a pre-filter between the tank and the Walbro. As a result, the sequence of fuel flow is…. . tank, Fram inline filter, Walbro pump, Permacool spin-on filter/separator, OEM filter canister, injection pump, 1/4" bypass hose, and then either the OEM return line or the secondary 3/16" return line.

While I had the tank dropped I also did the TDR tank vent mod. In addition, I took care of both of those tiny OEM gasser vents with some 3/16" fuel line, a tee, and a plastic Fram filter. I also modified the original tank vent for use by my secondary return line.

Under the hood, I purchased an aluminum fuel billet cap from Geno's for a Jeg's 0-60PSI gauge with a 45-degree elbow for easier viewing. I also used two tapped banjo bolts from Geno's for the injection pump bypass. On the input fitting of the injection pump I used a 1/4" stainless steel hose barb for the 1/4" bypass hose. On the output fitting I first installed a street-T with the 1/4" hose barb on the top for the same bypass hose. On the horizontal offshoot I then installed a second street-T with another 1/4" hose barb on the end, and a Jeg's 0-30PSI gauge on the offshoot. From this last 1/4" hose barb I ran a high pressure 3/16" fuel hose as a secondary return line (via the OEM tank vent fitting that was replaced by the TDR vent mod).

On the back side of the fuel filter bowl I used the FASS-II kit filter block and a 90-degree elbow to a 3/8" hose barb. I ran 3/8" high-pressure fuel line from the output of my Permacool filter up to the OEM filter canister. I also purchased the FASS wiring harness with relay, which really made for pain free wiring.

I don't have any fuel gauges in the cab, but with the underhood gauges at idle I'm seeing 20-22PSI pre-filter and 12-14PSI at the injection pump. I'm pretty happy with how the Walbro performed during the brief shakedown cruise. This new pump makes some noise when the engine is off (not too loud, it sounds just right), but once the engine is started I can't hear the Walbro at all. My engine idles very smoothly with the Walbro, and it seems to have the same power (or perhaps slightly more) than with the OEM lift pump.

I bought a second Walbro to carry as a spare, along with all of the filters and tools necessary to change the pump or any filter on the side of the road. It gives me peace of mind knowing that a bad lift pump will no longer strand me.

Pictures are located in my Reader's Rigs gallery below... .


https://www.turbodieselregister.com/user_gallery/displayalbum.php?&userid=16202&albumid=18305

 

[Gary - K7GLD]

VERY nice and rugged install - get back to us periodically with impressions of the pump as time and miles pass.

 

[lmills]

just did mine last weekend as well. So far it looks very promising

 

[Blacksdieselhp]

So where do you buy the Walbro pumps?

 

[lmills]

I got mine from a company on ebay called extreme psi. However, one of our tdr members is putting kits together. He goes by Gypsyman. PM him,he can fill you in

 

[Blacksdieselhp]

So why did you guys decide to use the Walbro pumps over other brands like Aeromotive, Holley, etc? They are just a EFI pump, correct? What are the advantages over the more popular brands?

 

[rbattelle]

Is that an inline pump (sure looks like it). What's the output pressure and flow rate?



-Ryan

 

[LSteiner]

Great Job

Excellent documentation!



Thanks

 

[Gary - K7GLD]

The Walbro comes in various flow rates and PSI - predominantly PSI up near or above 100 PSI, and flow rates from 80 GPH on up. The going theory with the Walbro pumps as added to our Dodges, is to install them similar to a pusher pump down closer to the tank, eliminating the stock LP, and using a bypass regulator to return excess PSI and flow back to the tank - and providing a more stable fuel flow and pressure to the VP-44.



Expectations thus far, are that the Walbro will survive better due to it's easier workload in our application, and better across the board fuel supply to the VP-44 due to the overkill the Walbro provides in fuel supply.



Only time will tell...

 

[MFalkinham]

The Walbro GSL-392 is an EFI pump that can be purchased from several vendors. I bought mine on eBay from a seller called fullthrottlespeed for $110 each plus shipping. As Gary-K7GLD mentioned it is a very powerful pump and capable of drawing up to 20 amps, so it should be run off a relay. The problem with using such a pump in a Dodge Ram Cummins is that if you don't provide some pressure relief the Walbro will build pressure until it cracks the plastic cover on the fuel canister.

Therefore you must either use a pressure regulator, or skip the regulator and just provide an open bypass at the CP3 for the excess fuel flow. Just running a 1/4" or 5/16" bypass hose from the CP3 inlet port to outlet port will give you around 20PSI at the inlet. In my case, I also ran a second 3/16" return line to the fuel tank which further lowered my CP3 pressure to 12-14PSI. Either way seems to work fine, with the theory being that the CP3 will take whatever fuel it needs from the inlet port and the excess fuel will flow back to the tank either through the CP3 or through the bypass.

The credit for the Walbro concept goes to Superduty on the cumminsforum.com site. As far as I know he was the first to try this in his 99 Ford (into which he custom fit an '05 Cummins ISB). The Walbro has caused much heated debate on some other Dodge Cummins forums, but at present there are about a dozen guys using it on 2nd and 3rd gen trucks, and so far the feedback has been positive.

 

[lmills]

there is only one down side to the open return line. It allows too much fuel to return to the tank when you are at wot. Mildly modified trucks are OK. However when you get into inectors and boxes together, it may draw down too low. Mine is currently pulling down to 5 psi at WOT with a 3/16" open return line.



I am going to go with Gypsymans recommendation and install a regulator. The regulator will close off the return line at WOT and allow all the fuel from the pump to go to the CP3. I think the pump will work just fine with my curent mods.



AND it's quiet, you can hardly hear it run.

 

[AEzzo]

Is that an inline pump (sure looks like it). What's the output pressure and flow rate?



-Ryan

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[AMassaro]

Been running the Walbro GSL392 for about 2000miles now. Idle has 23psi. 65mph I have 20-21psi. WOT and she goes to 12psi. This is with the bypass at the cp3. Others have run seperate bypass regulators to keep constant psi at all throttle conditions. I will run a bypass regulator when I step up the hp in the future.

btw - I'm also running an 85micron filter in front of the pump and soon will add the 2micron after the stock 10 micron...

 

[nickleinonen]

I'm also running an 85micron filter in front of the pump and soon will add the 2micron after the stock 10 micron...

something i want to do when i eventually upgrade my fuel sub system. . i will use a 15µ spin on filter before the new lift pump, then through the stock filter, then through a cat 2µ. . i just need to find/get some good quality filter heads. . i have some cast aluminum ones at home with a 1"-12 thread on them, but they are not pretty [would work for the 15µ, but not nice enough looking for the 2µ under the hood]



i want to run it regulated pressure, but with a boost reference signal to the regulator, so under load [boost] it will allow the fuel pressure to increase [eg. 10psi regulated 0psi boost, 25psi regulated 30psi boost, and variable values between the 0 and 30psi boost]

 

[Tomeygun]

i want to run it regulated pressure, but with a boost reference signal to the regulator, so under load [boost] it will allow the fuel pressure to increase [eg. 10psi regulated 0psi boost, 25psi regulated 30psi boost, and variable values between the 0 and 30psi boost]

Now thats what I'm talking about!



Most I have saw are boost refferenced at 1:1 - I would like about 0. 5:1 --



Idle FP - 15psi, add 40psi boost = 35psi fuel pressure



nice!!

 

[SLangegger]

Please excuse my ignorance, but can someone explain what the advantages are of having fuel pressure in a ratio with boost pressure? Why not just regulate to 20-22 psi all the time? Thanks in advance.



Steve

 

[Tomeygun]

Please excuse my ignorance, but can someone explain what the advantages are of having fuel pressure in a ratio with boost pressure? Why not just regulate to 20-22 psi all the time? Thanks in advance.



Steve

No problem!



It is because the maker of the modded CP3's are saying you need 40psi at the inlet to make the modded CP3 work as designed. But I dont like sitting there idleing at 40psi. So with this I can have my cake and chow down on it too! - 15psi at idle, and 40psi at higher RPM/Boost

 

[AMassaro]

I don't believe they make such an animal. The boost referenced bypass regulators are used, mostly, in carburated applications as we all know... They wouldn't work at anything less than 1 to 1 pressure ratios. Gonna have to be a custom regulator. I don't want to even think what that'd cost :--)

 

[lmills]

All you would need is a regulator for the boost that is set around 25 psi. the fuel regulator would be set at 15 psi for idle. At WOT, boost would build and as long as the boost regulator was set to 25 psi max, the fuel pressure would climb to 40 psi and then the boost signal would be neutered. The boost would continue to climb, but the boost refernce signal would not.

 

[Blacksdieselhp]

So doesn't the RASP work kindof like that? Couldn't you find a pump similar to the rasp that will idle around 15psi and gain the amount of psi you want v/s rpm and then just return what fuel isn't needed at higher rpms unless the boost was up? I may be way off, but just an idea. you guys are way ahead of me on this stuff. By the way does anyone know where the pump thats in the rasp kit comes from. I have found a couple that are very similar. I just don't see why the kit cost so much. The pump itself can't be much over $100. At least the ones I have found aren't and they were actually bigger than the one used in the rasp.