How exactly should I install a Walbro 400 pump in a 99-02 Silverado fuel bucket?
06-25-2016, 11:22 PM
#11
Here's what I decided to do.
Remember this pic?
Well, I took that rubber piece and trimmed it in a way where it'd fit on the Walbro pump.
Next, I placed that pump in the bucket, but first, I removed the one way rubber piece from the factory sock.
Here are my thoughts. The pump will now draw only from the factory sock, which is connected outside the bucket, and inside the bucket. There is a tube that is cast up into the bucket. Essentially this defeats utilizing the bucket as a reservoir but, allows for cooling the pump. The return fills the bucket which will overflow into the sock where the pump draws from. Unless of course the entire assembly is submerged under fuel.
The next issue is the fact that the pump is 0.481 inches shorter than I needed it to be. Remember when I build the stud mount coilover setup? Well, my first thought was to use delrin. After further research I discovered that delrin deforms and doesn't bounce back, a poor choice for suspension, but a good choice for being submerged in fuel.
So, I cut out a slice of delrin and then cut it in half. I placed this above the fuel pump which sandwiches it into place.
The next issue I faced was securing the pump. It is stuck in there pretty well, but I've also changed the design. The 2 pieces of the bucket weren't designed to hold the pump in place. At first I was planning on using stainless steel zip ties, then I remembered the wire I used for securing my dirt bike grips.
This is something I picked up a while back at Harbor Freight. It claims it'll hold up. Here's hoping!
Now, fitting the submersible fuel line in place to the pump was very straight forward, the top was pretty tight. I ended up using a 1/4" end wrench, one tiny turn at a time.
Also seen here is the upgraded and rewired connector.
Sorry for the messy workspace. All done.
I'm wondering if I should secure the wires at all? Maybe to the fuel line itself? Also, I had considered soldering the power lines to the pump terminals, but I think they'll hold.
Remember this pic?
Well, I took that rubber piece and trimmed it in a way where it'd fit on the Walbro pump.
Next, I placed that pump in the bucket, but first, I removed the one way rubber piece from the factory sock.
Here are my thoughts. The pump will now draw only from the factory sock, which is connected outside the bucket, and inside the bucket. There is a tube that is cast up into the bucket. Essentially this defeats utilizing the bucket as a reservoir but, allows for cooling the pump. The return fills the bucket which will overflow into the sock where the pump draws from. Unless of course the entire assembly is submerged under fuel.
The next issue is the fact that the pump is 0.481 inches shorter than I needed it to be. Remember when I build the stud mount coilover setup? Well, my first thought was to use delrin. After further research I discovered that delrin deforms and doesn't bounce back, a poor choice for suspension, but a good choice for being submerged in fuel.
So, I cut out a slice of delrin and then cut it in half. I placed this above the fuel pump which sandwiches it into place.
The next issue I faced was securing the pump. It is stuck in there pretty well, but I've also changed the design. The 2 pieces of the bucket weren't designed to hold the pump in place. At first I was planning on using stainless steel zip ties, then I remembered the wire I used for securing my dirt bike grips.
This is something I picked up a while back at Harbor Freight. It claims it'll hold up. Here's hoping!
Now, fitting the submersible fuel line in place to the pump was very straight forward, the top was pretty tight. I ended up using a 1/4" end wrench, one tiny turn at a time.
Also seen here is the upgraded and rewired connector.
Sorry for the messy workspace. All done.
I'm wondering if I should secure the wires at all? Maybe to the fuel line itself? Also, I had considered soldering the power lines to the pump terminals, but I think they'll hold.
06-27-2016, 04:01 AM
#12
Just to keep this thread updated...
Installed the Hotwire kit. I ran the line along the frame rail on the driver's side. I highlighted in blue how the wire is ran. It goes to a fuse and then directly to the alternator.
Right here you can see where there is a factory ground point. This is on the driver's side right behind the cab. The factory loom and the fuel fill hose is grounded at this point. I decided to ground the fuel pump wiring kit here as well. To get the harness to reach, I had to remove a factory bracket, install the wiring kit's ground underneath and reinstall the bracket.
From a different angle. You can see in the center near the fill hose the hotwire kit's relay laying down.
I had so much extra wire that I ran it across to the other side and back. That's what the 3 zip ties are doing. I'll trim them up when I get the wiring exactly where I want it and put everything back together.
When I installed the fuel pressure gauge in March, this was my fuel pressure:
55-58ish
Before I put everything back together I started the truck up to test everything out. It started right up. I let it idle for a few minutes. Here is my current fuel pressure:
72ish
Okay, so is this an indication of my fuel pressure regulator failing to keep up with the Walbro pump? If so, what's next? Either ebay fuel rails and an external fuel pressure regulator. Or, I need to figure out how to bypass the factory regulator. To my surprise, finding a billet plug/cap is much harder than I thought it'd be. I was hoping that there may be an aftermarket FPR that is vacuum referenced and adjustable, that'd fit in the fuel rail.
Also, I tested the regulator by pulling the vacuum line off and on several times. The fuel pressure didn't change much, but I'm wondering this: Do you guys think maybe a factory replacement regulator would maybe keep up?
The reason I ask, is because I ended up pulling off the vacuum line to show my step father and fuel came out. This indicates failure to me. I wonder if the regulator was weak and the pump caused failure or something along those lines? I have read that the factory FPR Will hold up to the Walbro 400. It's one of the reasons I went with it over the 450.
Installed the Hotwire kit. I ran the line along the frame rail on the driver's side. I highlighted in blue how the wire is ran. It goes to a fuse and then directly to the alternator.
Right here you can see where there is a factory ground point. This is on the driver's side right behind the cab. The factory loom and the fuel fill hose is grounded at this point. I decided to ground the fuel pump wiring kit here as well. To get the harness to reach, I had to remove a factory bracket, install the wiring kit's ground underneath and reinstall the bracket.
From a different angle. You can see in the center near the fill hose the hotwire kit's relay laying down.
I had so much extra wire that I ran it across to the other side and back. That's what the 3 zip ties are doing. I'll trim them up when I get the wiring exactly where I want it and put everything back together.
When I installed the fuel pressure gauge in March, this was my fuel pressure:
55-58ish
Before I put everything back together I started the truck up to test everything out. It started right up. I let it idle for a few minutes. Here is my current fuel pressure:
72ish
Okay, so is this an indication of my fuel pressure regulator failing to keep up with the Walbro pump? If so, what's next? Either ebay fuel rails and an external fuel pressure regulator. Or, I need to figure out how to bypass the factory regulator. To my surprise, finding a billet plug/cap is much harder than I thought it'd be. I was hoping that there may be an aftermarket FPR that is vacuum referenced and adjustable, that'd fit in the fuel rail.
Also, I tested the regulator by pulling the vacuum line off and on several times. The fuel pressure didn't change much, but I'm wondering this: Do you guys think maybe a factory replacement regulator would maybe keep up?
The reason I ask, is because I ended up pulling off the vacuum line to show my step father and fuel came out. This indicates failure to me. I wonder if the regulator was weak and the pump caused failure or something along those lines? I have read that the factory FPR Will hold up to the Walbro 400. It's one of the reasons I went with it over the 450.
06-27-2016, 06:54 AM
#13
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Sorry I was away for the weekend with limited service.
The install looks good.
The 72 psi fuel pressure, my guess would be that you are overdriveing the regulator with the upgraded fuel pump. I would suspect a new regulator is in order.
Is your truck boosted? or plan to be? If so I would probably go with a nice boost referenced regulator as they tend to be more "hearty" than the O.E.M units.
The install looks good.
The 72 psi fuel pressure, my guess would be that you are overdriveing the regulator with the upgraded fuel pump. I would suspect a new regulator is in order.
Is your truck boosted? or plan to be? If so I would probably go with a nice boost referenced regulator as they tend to be more "hearty" than the O.E.M units.
06-27-2016, 03:15 PM
#14
Sorry I was away for the weekend with limited service.
The install looks good.
The 72 psi fuel pressure, my guess would be that you are overdriveing the regulator with the upgraded fuel pump. I would suspect a new regulator is in order.
Is your truck boosted? or plan to be? If so I would probably go with a nice boost referenced regulator as they tend to be more "hearty" than the O.E.M units.
The install looks good.
The 72 psi fuel pressure, my guess would be that you are overdriveing the regulator with the upgraded fuel pump. I would suspect a new regulator is in order.
Is your truck boosted? or plan to be? If so I would probably go with a nice boost referenced regulator as they tend to be more "hearty" than the O.E.M units.
Right now, the factory fuel pressure regulator is failing. I think I'm going to try to replace it with a factory piece. The problem I have, and suspect many others in my situation has had, is I don't really need aftermarket fuel rails. What I do need is a way to bypass the factory regulator.
That's why I made this thread:
https://www.performancetrucks.net/fo...uy-one-544768/
I will buy aftermarket rails if I absolutely have to, but would rather not if the factory ones will work for me. If I can source that block off piece, then I'll likely go with an aeromotive boost referenced fuel pressure regulator. I'm looking into it right now.
The plan is to be boosted. Nothing crazy though. 76mm turbo with intercooler. I'm hoping for 700-750 horsepower at the engine. I believe that is about the limit of this fuel pump.
Thanks for the help!
07-09-2016, 06:25 PM
#16
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i bought a fuel pressure regulator block off from ebay. it was 12.50. supposedly designed for a bmw but its the same regulator that was on my truck. i cross referenced the part numbers and they matched so i figured the block off should work and it does.
http://www.ebay.com/itm/BMW-fuel-pre...tW6IRi&vxp=mtr
http://www.ebay.com/itm/BMW-fuel-pre...tW6IRi&vxp=mtr
07-09-2016, 07:03 PM
#17
You need aftermarket rails and regulator.
The design of the stock is such that the fuel has to flow thru a tiny orfice in the regulator housing before feeding the rails. You can try blocking the regulator but im confident you'll still have high pressure.
The design of the stock is such that the fuel has to flow thru a tiny orfice in the regulator housing before feeding the rails. You can try blocking the regulator but im confident you'll still have high pressure.
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