Trying to Instal a Walbro/CP3 Bypass System???
Just thought I should post this from Gypsyman who is working to release a retrofit kit in the next few days once he gets his vendor dues payed here, so I can't say much else. So without further addoo!!!!
Here's a couple of quick pictures of his bypass system at the filter. This gives 17 psi post filter and 20 psi pre-filter.

This is shown on an '05 filter canister and the connection at the right is where his filter adapter will go on an '03/'04 truck. The 90* fitting in the top left is the only other connection made. So you mount the adapter in place of the factory LP, replace on banjo with a tapped version, connect the bypass line to the tapped banjo, and hook the new fuel line to the existing factory hard feed line. Pretty simple huh?
Edit: Sorry to Gypsyman and the ones who read my earlier unedited
but Gypsyman advised me I may cause him to be in violation of site
rules regarding vendor advertising so therefore I deleted much info. I
definately don't want to cause him any grief over this, cause I plan to
be one of his customers.
Here's a couple of quick pictures of his bypass system at the filter. This gives 17 psi post filter and 20 psi pre-filter.

This is shown on an '05 filter canister and the connection at the right is where his filter adapter will go on an '03/'04 truck. The 90* fitting in the top left is the only other connection made. So you mount the adapter in place of the factory LP, replace on banjo with a tapped version, connect the bypass line to the tapped banjo, and hook the new fuel line to the existing factory hard feed line. Pretty simple huh?
Edit: Sorry to Gypsyman and the ones who read my earlier unedited
but Gypsyman advised me I may cause him to be in violation of site
rules regarding vendor advertising so therefore I deleted much info. I
definately don't want to cause him any grief over this, cause I plan to
be one of his customers.
Last edited by streetsmoker; Mar 3, 2006 at 11:14 PM. Reason: Deleting Info Gysyman Said Conflicted with Site Rules Regarding Vendors Advertising
Gsl 391
I was just wondering why the kit comes with the GSL 391 pump and not the
GSL 392 pump? From the flow charts I quickly checked it flows about 20 GPH less.
On another note I think it's great that someone is putting a kit together with all the parts needed.
On Edit: Sorry I guess i didnt go to the next page. I now see the explanation on the pumps.
GSL 392 pump? From the flow charts I quickly checked it flows about 20 GPH less.
On another note I think it's great that someone is putting a kit together with all the parts needed.

On Edit: Sorry I guess i didnt go to the next page. I now see the explanation on the pumps.
Just found this thread. Looks good so far. It's amazing how many different ways you could plumb a Walbro, or any efi pump for that matter. Use a regulator, a bypass at the cp3, a bypass before the filter, etc.
I have the plain ole original "Superduty" bypass plumbed with a fuel pressure guage.
Green04 is using the "regulator" which is most likely the best.
And now Gypsyman with his setup. From what I can tell it looks promising in that you don't have to touch the cp3 which might give a leg to stand on with warranty issues. On the other hand, all the fuel isn't being filtered and sent thru the cp3 for cooling and lube. It's being sent back before the filter. Pluses and minuses for all. To me the regulator is sweet but probably the most costly. When I step up to twins, I'll go that route.
I have the plain ole original "Superduty" bypass plumbed with a fuel pressure guage.
Green04 is using the "regulator" which is most likely the best.
And now Gypsyman with his setup. From what I can tell it looks promising in that you don't have to touch the cp3 which might give a leg to stand on with warranty issues. On the other hand, all the fuel isn't being filtered and sent thru the cp3 for cooling and lube. It's being sent back before the filter. Pluses and minuses for all. To me the regulator is sweet but probably the most costly. When I step up to twins, I'll go that route.
Originally Posted by Green04HO
I was just wondering why the kit comes with the GSL 391 pump and not the
GSL 392 pump? From the flow charts I quickly checked it flows about 20 GPH less.
On another note I think it's great that someone is putting a kit together with all the parts needed.
On Edit: Sorry I guess i didnt go to the next page. I now see the explanation on the pumps.
GSL 392 pump? From the flow charts I quickly checked it flows about 20 GPH less.
On another note I think it's great that someone is putting a kit together with all the parts needed.

On Edit: Sorry I guess i didnt go to the next page. I now see the explanation on the pumps.
why? what r u reading?
streetsmoker added new pictures and info to his post as to why they were going
to use the smaller pump. He also posted that they were going to be comming out with a kit for the larger pump.Look back at the post before mine.
to use the smaller pump. He also posted that they were going to be comming out with a kit for the larger pump.Look back at the post before mine.
Walbro is finally done!
I just finished with the complete install. Pre-filter pressure is approx. 17 PSI and Idle-WOT is 14-15 PSI. It drops to 14 for a second then goes back to 15.
Somthing I found worth noting is that now my truck lets out a nice little cloud till the turbo spools. It has never done this before so I must assume that I was running out of fuel before.
Somthing I found worth noting is that now my truck lets out a nice little cloud till the turbo spools. It has never done this before so I must assume that I was running out of fuel before.
Glad to here it went well. Pretty soon Superduty will be vindicated and those who torched him will have to eat crow.
Which way did you route your bypass? Did you use a regulator? What Walbro did you go with? Oh, and one more thing:
Post pics!!!!!!
Which way did you route your bypass? Did you use a regulator? What Walbro did you go with? Oh, and one more thing:
Post pics!!!!!!
I installed the pump in the supply line and mounted it to the frame.Then I disconnected the supply line from the stock LP and connected it to the filter housing. Next I put a tee fitting in the line from the filter to the IP and another tee in the plastic return line (the plastic line runs from the motor to the 1/4" steel line on the frame) and ran a 5/16 line from tee to tee.Thats the bypass.
I used the stock LP wiring to trigger a relay to run the Walbro pump.
Now, I have stock fuel lines, the restriction of the 1/4 return line is giving me the psi at the IP I have. 14-15 cruising.
I used the stock LP wiring to trigger a relay to run the Walbro pump.
Now, I have stock fuel lines, the restriction of the 1/4 return line is giving me the psi at the IP I have. 14-15 cruising.
Which way did you route your bypass?
Did you use a regulator?
What Walbro did you go with?
I will try to take some more pics later.
Wow! I'm getting stoked. When I get some free time I guess I'll crawl under the truck nd slap it all together. You guys have given me a few other options to consider when I finally decide to tackle this project.
Originally Posted by DF5152
is the additional relay really necessary?



