This is a thread for those people building a Walbro fuel system to discuss their installation. I used the term Walbro, but I mean implementing a fuel system with a high pressure fuel injection type pump, be it Bosch, Walbro, etc.

I am putting this in general diesel because the 2nd and 3rd gen installations are basically the same, save the CP3 has a built in lift pump that can be fed differently than a VP44.

The installation of FASS, RASP, carburetor type Holley and Carter pumps should not be discussed here, except as examples to help out the people implementing Walbro systems.

If you get here and are scratching your head about things, a complete discussion of stuff can be found here:

https://www.dieseltruckresource.com/...ad.php?t=88136

Don't PM me. Ask your question in one of these threads so that everyone can see the answer.


Parts Sources:

Walbro Pumps:

http://www.autoperformanceengineerin.../ext_pump.html

Google and you will find other sources. I just used that link because they had good information on Walbro pumps.

BTW: Walbro makes carburetor type pumps too. DON'T USE THEM.

Here is an example of what not to use:

http://www.autoperformanceengineeri.../6000_pump.html


Another Walbro site with curves.
http://shopping.lightningmotorsports...55lph-p-8.html

Same site: in tank Walbro pumps, 255L, like the 392. One is a high pressure model that goes to 150 PSI.

google <walbro pump wholesale> and lots of suppliers show up.


Here is a source of tapped banjo bolts:

http://www.genosgarage.com/CoastalD..._ID=593&CATID=1

Regulators:

I don't think a 2 port Holley type regulator will work.

Such a regulator will regulate the fuel pressure downstream of the regulator, but it won't spill the excess fuel to the return line. You need a regulator that will spill excess fuel.

I think you need a 3 port regulator like a 12-803BP.

If it was a returning regulator, you would plumb it like figure 2a in this diagram, putting the injection pump where they have the carburetor.

http://www.holley.com/data/Products.../199R7914-3.pdf


Here is a swagelok regulator. It is my favorite.

B-4CPA2-DG-3

Description: Brass 1-Piece Poppet Check Valve, Adjustable Pressure,1/4 in. MNPT, 3 to 50 psig (0.21 to 3.5 bar), Green Deflector Cap

It looks exactly like a longish 1/4" hex nipple, if you know what that is, but inside it is an adjustable pressure relief.

It is the fitting in the lower right hand corner of the cover of this catalog:

http://www.swagelok.com/downloads/we.../MS-01-176.PDF

You have to disconnect the line to set the pressure with these. But they are very compact, just a 1/4" nipple is all. They regulate well too.

Could use a Holley type regulator as well.

I have no affiliation with Swagelock. I just like their stuff. Ditto Bosch, Walbro, Geno, Holley, etc.


www.mcmaster-carr.com as well, but I couldn't find any that are adjustable.

 

"I get a Walbro gsl-392, then I will need a pressure regulator also, correct?"

Yep. If you want to pressure feed the injection pump.

If you have a CP3 and you don't want a regulated pressure feed for it, just use the bypass with no regulator.

 

How would one go about removing the stock lift pump on the fuel filter on the 2004 305/555 motor? From the manual i have it seems like the fuel line comes off of the frame rail and goes to the lift pump.
From this point the lift pump uses some kind of o-ring setup that is press fit into the filter housing and held in by four allen screws.

How could you pick up the fuel line at the frame rail and continue it to the filter?

 

I can't answer this. I don't have an 03ish Dodge nor a shop manual.

I am sure that someone else will chime in with an answer, and hopefully pictures too.

 

"The biggest problem with lift pumps isn't necessiarly the brand, or type, but the mounting location. If the stock pump is moved off the engine, to the frame, back by the tank, pump life is lengthened considerably. Its takes a pretty tough pump that will last through the heat, vibration, and VP44 harmonics that are associated with the stock mounting location."

Yep.

A great place to mount them is on the inside of the frame rail on the drivers side. Just splice into the supply line. The Walbro will easily fit. I'll take a picture of mine mounted on my Ford. The Walbro sites have a mounting kit you can buy.

It is also the heat more than anything, especially with the air cooled pumps.

 

Here is a starting point for a parts list.

The Walbros come with a mounting kit or you can buy one for it. I would just bolt it to the frame rail and wire it up. Cut the supply line from the tank and splice in the Walbro. You guys with pumps in the tank will have to drop your tank and pull the pump. Yuck, I know, but not killer.

The whole parts list for a CP3 setup would be:

1 Walbro and mount be sure to get the right inlet/outlet on it
2 drilled and tapped Banjo bolts for the CP3 bypass
2 3/16" x 1/8" M NPT hose barbs for the bypass
1 piece of hose for the bypass (3/16")
1 1/8 M NPT x 3/8"(?) nose barbs for the suction side of the pump.
1 short pieces of 3/8" hose for the splice
Hose clamps
1 1/8" M NPT x 3/8(?) compression fitting to attach the Walbro to the supply line
Wire and connectors.

If you want to run a pressure gauge at the CP3, you'll have to T into the supply side of the bypass line. If I were running a bypass I would just watch the pressure upstream of the filter on the engine.

People wanting a pressurized injection pump supply (CP3 or VP44) will need to put a regulator into the bypass. I'd run a piece of steel tubing rather than the plastic stuff if I were running a pressurized system.

Instead of the 3/16" hose barbs and hose, I'd use:

2 x 1/8" M NPT -1/4" tube compression fittings (connect to the banjos)
2 x 1/4" tube x 1/4" F NPT splice in the pressure regulator
1 1/4" pressure regulator (SwageLock style)
1 foot of 1/4" tubing

Or something like that.


The guys with in tank pumps will need to rig up a tank pickup system. I'd look at the pickups used in the 03.5s to see how they did it. (03.5s have the fuel pump mounted on the engine, right ? Bad place btw: heat and vibration. What were they thinking ?)

Making a fuel pickup out of a tank with an in tank pump might be as easy as removing the pump and replacing it with a piece of hose.

I think the Walbro can mount right in the tank if it was wanted as such.

People with the engine mounted fuel pumps could mount the Walbro there as well. The foam cradle it mounts in will help isolate a bit of the engine vibration. I'd connect it with rubber lines to get more isolation. Should be pretty straight forward.

 

Here is a picture of the Walbro mounted on the inside frame rail of my truck, in the holder that the Bosch sat in.

I didn't realize the cradle was lopsided like that until I looked at the picture. I'll have to fix that. I'm embarrassed.

This pump fueled the Powerstroke that was in before the Cummins for about 60,000 miles at 70 PSI. I put it in and haven't looked at it since. One can't hear it run in the cab and you can hardly hear it run outside. You won't hear it with the engine running.

In July it made enough pressure to crack the filter housing. It is now running at about 10 PSI of backpressure. It should go for a long, long time without any trouble.

The line under the pump is the return line.

The suction line is on the left. It goes to the fuel tank. The supply line going to the engine is on the right. That blue line is the stock Ford line. It clicked right into the quick connector on the Cummins fuel filter assembly. Even the line length was right.

 

"If I was to run this system with the Walbro, what precautions would I need to know about concerning disconnecting the fuel lines at the cp3?"

Nothing special, just keep everything clean. The CP3 inlet side self bleeds, so nothing to do there.

Don't use teflon tape on any fittings. I recommend using all brass fittings. Steel fittings are yucky. SS fittings seal harder. Brass is softer and seals nicely. NO GALVANIZED FITTINGS.

I'd pressure wash the CP3 and let it dry before I worked on it.

Take your time and be safe.

Post your pictures and experience here for others to use.

"Also, was it determined or not if we need something to fool the ecm when connecting the higher draw motor of the walbro?"

Good question. On the 05, the ECM provides an open collector output to drive the fuel pump via a wire comming from the engine connector. (C130 if you are looking at a wiring diagram.) An open collector output is like a relay where the other side of the contact goes to ground. Except it isn't a relay, it is a transistor.

That open collector output goes to a relay. The one side of the relay coil goes to 12V and the other side goes to the open collector ECM output. So... when the ECM wants the fuel pump to run the open collector output goes to GND, the relay coil sees 12V on one side and GND on the other. Current flows through the coil. The relay contact closes and your fuel pump runs.

BTW: It is collect a collector because that is the part of the transistor that the wire connects to. The emitter is tied to ground. The base is driven by the computer in the ECM.

Now... I'll add some info here that caused us a lot of grief when we put the Cummins in my Ford.

1) The ECM doesn't run the fuel pump all the time. When you turn the key on and not turn the engine over, it runs for 5 seconds and shuts off.

2) If you crank the engine it runs the pump for 20 seconds after you stop cranking.

I think the reason it does this is that there is no pressure relief on the Dodge pumps and if the engine isn't running then the pump is straining against a dead end. Very bad for the pump.

3) Open collector outputs don't go to 12V unless they are hooked to something. So if you pull the fuel pump relay out of your truck and put a voltmeter on the fuel pump ECM wire, it will read something stupid like 0.8 Volts when the pump wouldn't be running and 0.2 volts when it would be running. Don't expect to see 12V on that wire if the relay isn't hooked to it.

BTW: the relay is in the Power Distribution Center box. Your owners manual should show you where it is.

OK. The Dodge shop manual, on page 14-125 (Volume 3) it states that the maximum current flow to the pump is 5 Amps. That doesn't mean the maximum current flow the relay will take is 5A. They don't tell us that.

If you look at the Walbro flow curve, you'll see that it draws 5A at about 10 PSI and 6A at 20 PSI and 7A at 37 PSI. I don't think you'll run much more pressure than that.

So... CP3 trucks using a plain bypass probably don't have to touch the relay. It will work fine because your backpressure at the pump is about 6-8 PSI with a clean filter.

Trucks running a regulator will need to look at what sort of pressure they are running and go from there. I expect, but cannot guarantee that the stock relay would handle 7A without much trouble. Time will tell.

If you don't want to take that chance, you have a couple options.

First you could replace the stock relay with one of more current handling ability. If you do so, you connect one side of the new relay coil to 12V and the other side to the open collector relay output from the ECM. On my truck the Cummins ECM operates the stock Ford relay and this is how we did it.

One could also wire a second relay into the system, having the stock relay drive the second relay's coil. To run like this, you'd cut the wire going to the fuel pump and use it to power the coil on the second relay. Then you would hook the wire still going to the fuel pump to the contacts on the second relay. Make sense ?

The last option would be to select a different pump. All along I've spoken of the Walbro GSL 392, but any good high pressure fuel cooled fuel injection style gerotor pump designed for diesel fuel will work, including the smaller Walbros. The 392 is really overkill for a lot of applications. A smaller pump (40 GPH @ 20) would work fine for stockish HP levels. I think Holley makes these pumps and I see that Carter does to, so you might want to check them out.

DO NOT BUY A PUMP UNLESS YOU SEE A DELIVERY CURVE AND IT LOOKS GOOD. If the manufacturer can't take the time to tell you what the pump does and how it is built, then find another pump.

If it helps, the Walbro 392 in my Ford draws more current than the stock Bosch pump did. We didn't change the relay and it has never given a stitch of trouble. If the relay burnt out tomorrow I would buy 2, using one to replace the burnt one and the second as a spare. Relays are usually over designed. Actually it is usually possible to blow the fuse protecting the relay and not damage the relay. I think the 5A rating in the shop manual was the pump limit, not the relay limit.

But I cannot guarantee you any of this.

Hope this helps.

 

SD,
Do you see any problems I would have leaving the stock in tank pump feeding into the Walbro? Actually, I'm thinking of going from stock in tank pump to 2micron CAT filter feeding into the Walbro then heading to the stock fuel filter. I know it's backwards to have the 2micron before the 10micron, but I don't think I have the room to install the CAT filter after the stock one. I'd also use a seperate relay to run the Walbro with it's own seperately fused circuit.

btw- someday I'd like to have 500hp and I think with this setup, I should be ready

Thanks again,
Tony

 

Concerning removal of the stock lift pump mounted on the filter housing, what has Dodge done when they retrofit the 05 type in-tank pump to an 03-04.5 filter mounted pump? I know that when an 03-04.5 pump is replaced under warrenty they put the in-tank pump in instead.

Does anybody know what they do about the old pump? Do they remove it and put some kind of plate or fitting where the old pump was or do they just leave it and pump through it?

Alternately, what does FASS make you do about the old pump when you install just the FASS pump?

 

"... but I like this Walbro pump idea! I'm getting ready to do my VP and was going to do the LP at the same time (even though it's only got 10K on it). Has anyone with 2nd gen done this mod?"

I dunno. People can chime in here if they have. It isn't just my thread.

"I'd like some info on how to hook the system up (placement/type of regulator, etc.)."

That is what this thread is for. If I was doing a 24V (VP44), I'd either mount the lift pump on the engine or on a frame rail like it is on my Ford. (See the picture above. I prefer the later.) You'll need a pressure regulator in the bypass line, like in the diagram below.

The second implementation, with the regulator at the injection pump, gives better pressure regulation as the diagram explains.



"I've got the Vulcan relocation kit installed. Would I have to upgrade the hose to the "fuel injection" type, since this pump is capable of hitting higher pressures?"

Not if you keep the regulated pressure below the safe pressure of the lines.

 

"Do you see any problems I would have leaving the stock in tank pump feeding into the Walbro?"

I dunno for sure. I don't recommend it. People say the second lift pump can suck fuel through the in tank pump, but obviously it makes the job of the second pump harder.

"Actually, I'm thinking of going from stock in tank pump to 2micron CAT filter feeding into the Walbro then heading to the stock fuel filter. I know it's backwards to have the 2micron before the 10micron, but I don't think I have the room to install the CAT filter after the stock one."

I am one step ahead of you on this. I bought the Cat filter and there is room. I've got some ideas on the filter head and mounting and I will be mounting mine between the stock filter and the CP3. I don't know if it is a good idea to mount a 2 micron filter on the suction side of a pump. I'd feel more comfortable with a 10 micron filter on the suction side.

"I'd also use a seperate relay to run the Walbro with it's own seperately fused circuit."

Sounds good.

"btw- someday I'd like to have 500hp and I think with this setup, I should be ready"

I think you will be.

"Concerning removal of the stock lift pump mounted on the filter housing, what has Dodge done when they retrofit the 05 type in-tank pump to an 03-04.5 filter mounted pump?"

I dunno what people have done. If you've done something, please report it here.

"I know that when an 03-04.5 pump is replaced under warrenty they put the in-tank pump in instead."

Yes they do.

"Does anybody know what they do about the old pump? Do they remove it and put some kind of plate or fitting where the old pump was or do they just leave it and pump through it?"

Good questions. Guys ? Do you have some answers ?

"Alternately, what does FASS make you do about the old pump when you install just the FASS pump?"

If it was me, I'd drop the tank and put a section of hose where the in tank pump was. One could also get the tank pickups that they throw out when they retrofit an engine mounted pump with an in tank pump.

 

I've been doing a little bit of research on this. BD has an adaptor with o-ring. (part # 1502028/1502029) Part of a kit. Don't know if they sell it seperate.

They also reference a Chrysler part # for fuel line from frame to filter.
(part # 5133196AB)

 

I went on the DPP/FASS website and looked at the instruction for the pump only kit. They make an aluminum adapter that bolts in place of the old pump. They call it a Filter Plate and the part # is FP-1001. I'm going to see if I can get just that part from one of their dealers.

If you want to see what it looks like, go to http://www.dieselpp.com/ and click on the installation instructions for the Fass Fuel Pump.

 

Superduty, let me get this right!

According to your diagrams above, as long as you have a regulator set at 15 PSI, somewhere in the system, you'll never see more than 22 PSI from the lift pump? So, placing the regulator just before the VP would insure the pump was fed a constant 15 PSI ... am I correct?