View Full Version : Lost's fuel pump project

02-26-2011, 07:56 AM
I was wondering if anyone had added a fuel return line? one of the things you can do with a fuel pressure regulator on a cab setup, is add a return line with a small orifice in it to the incoming fuel line, this always lets a small amount of fuel return to the tank, preventing presssue creep behind the regulator, you just need to make sure the pump has enough capacity to keep the bowls filled plus the very small amount of pressure bleeding off. I was wonding who had added a line to maby do a FI setup, I was wanting to see how the line was routed.

02-26-2011, 09:35 AM
Hehehehehe! You said "orifice." Hehehehe hehehe hehe heheheheheh!

02-26-2011, 09:45 AM

02-26-2011, 05:38 PM
I decided to use a facet pump, I guess i could add the return line right after the pressure side of the pump, basically what it is ,is a fitting brazed shut, with a 1/32 hole drilled in the braze, this allows a very slow leak of fuel back to the tank, this stops pressure creep from right behind the regulator, i need to find the formula to figure out exactly how big the hole needs to be, but I need to know the demand of fuel at mid throttle to calculate it. Thats going to be hard to figure out

02-26-2011, 08:10 PM
got my pickup installed in the tank finally, I can't believe the poor quality of the in tank pumps available for this car, I have an original pump on a hanger, and two aftermarket pumps and hangers, and every one is different, hangers are different lengths, the aftermarket pumps look like cheap junk, and they are supposed to all be the same, and don't get me started on the carter pumps, complete garbage, i had six fail in a row, the counter person at Oreilies told me they discontinued the brand,so many came back, It's a little tough to find a low pressure in tank pump, at least a quality one. I'm just going to install a good facet pump under the car. This is my hanger I created to replace the pump, http://i220.photobucket.com/albums/dd158/lostforawhile/IMG_1297.jpg

I'm going to create a bypass to let a small amount of fuel cycle back to the tank, This prevents fuel pressure creep behind the regulator, I ended up drilling out the rivet holding in the old electrical connector, and drilled and tapped for 1/8 npt, pretty heavy material in this hanger, and installed a 1/8 to -4 right angle. I have a fitting i made that is brazed up with a 1/32 hole drilled through the braze, this allows a controlled amount of fuel to cycle back to the tank

03-03-2011, 06:37 PM
I've been under the back end of the car the last two hours, I had to make some templates, I need to fit the fuel filter and pump under there somehow,I have the Facet pump coming, I now have a car sponsor, long story....


03-03-2011, 06:41 PM
I'm waiting for my facet pump to get here, I borrowed one from work which is identical to the one I ordered, This is the plate with the filter and pump, I'm using three exisiting unused threaded holes on the frame rail to bolt this to.

pattern transferred to steel plate
I use 3M vhb tape to hold the patten for marking the plate



03-03-2011, 06:42 PM
well this is what my new pump will look like, It should be here in a couple of days


this is what it looks like under the car, I finally figured out how to run the lines to hook everything up, i'm just waiting on a fitting. I still need to make a stone guard for the pump


03-03-2011, 06:45 PM
I got more done on the fuel pump, I wanted to add something to protect the pump and filter from flying road debris,

these are the end brackets, I already had cut them, and drilled and tapped them

the finished bracket

milling the support brackets

bottom plate





I'm still waiting on some fittings to come in, as well as the actual pump, should be here tomorrow

Vanilla Sky
03-03-2011, 07:08 PM
You know, this is searchable. The LXi has a return.

03-03-2011, 07:15 PM
Lostforawhile wouldn't be Lostforawhile if he didn't fab it all up his own way. nice work, bud

03-03-2011, 07:31 PM
You know, this is searchable. The LXi has a return.

i started this as one thread, I think I'm going to change the title and have this moved to the projects forum as a new fuel pump thread instead, I'm aware the LXI has it's own fuel return line, but i was wondering about who had done their own

03-04-2011, 02:20 PM
This was going to be the side cover, but I left it on my bench at the house this morning, doh, so i started over.

This is the new cover, I already put the hole in the center of it on the mill. The hole is needed to clear the bolts on the filter

while deburring the hole, I decided it was a good time to give blood,

I needed something to cover the hole, ( the cover hole, not the hole in my thumb) so I used an old wheel hub,



03-04-2011, 02:21 PM

of course it needs paint, other then the center cap, and i need to finish putting the rivets in the lower bracket, but it all fits. I think this will protect the pump and filter well



03-04-2011, 10:01 PM
went out there, cranked up bluesville on the big speakers in the loft and did some more. The new pump should be here tomorrow, the fitting from Summit already made it here.

03-05-2011, 09:23 PM
The pump got here today, looks good, I'm baking the pieces of the bracketry right now, and getting ready to put them back together, pictures up in a bit

03-05-2011, 09:55 PM
What would it take to get you to make one of those pump hanger inserts for me? It looks clean as hell.

03-05-2011, 10:21 PM
What would it take to get you to make one of those pump hanger inserts for me? It looks clean as hell.

i'll have to see if I have any more of the wide aluminum stock

03-06-2011, 01:22 AM

03-06-2011, 08:07 PM
I bolted up everything, and everything clears.


this was the original filter bracket before I got the pump and built this one


03-06-2011, 08:25 PM
Woah, your original pump mounting was way far and above what I've got. The new setup looks like it came from inside a computer or something.

I like the hole saw in the mill. I've only got 2 manual mills with drills up to 3.5" dia, and a Haas VF-7, monstrous table, run by Mastercam.

Back to the fuel pump, I just Pico clamped mine to the bottom of the car, but the biggest pico clamps weren't big enough, so I used a couple joined together with a bolt and nut. Since the pump body itself rests against the bottom of the car, it's loud as hell. Pump comes on, you hear it. But that's an EFI pump. I also used cheap fittings, brass double flare and high pressure style fuel line clamps with brass hose barbs.

03-06-2011, 08:32 PM
Woah, your original pump mounting was way far and above what I've got. The new setup looks like it came from inside a computer or something.

I like the hole saw in the mill. I've only got 2 manual mills with drills up to 3.5" dia, and a Haas VF-7, monstrous table, run by Mastercam.

Back to the fuel pump, I just Pico clamped mine to the bottom of the car, but the biggest pico clamps weren't big enough, so I used a couple joined together with a bolt and nut. Since the pump body itself rests against the bottom of the car, it's loud as hell. Pump comes on, you hear it. But that's an EFI pump. I also used cheap fittings, brass double flare and high pressure style fuel line clamps with brass hose barbs.I used the mill with the hole saw, because I can run it in back gear and slow the saw way down, the sound of a hole saw on high speed on thin aluminum is a sound heard all over the plant. I just drilled three holes in the piece, screwed it to a 2/4 and clamped that in the mill. I drilled the 1/4 inch hole on center on the drill press, the center on the hole saw is just a 1/4 round pin. We do a lot of the hole drilling like that, aluminum,stainless, etc. the cage around the pump is to protect it from flying road debris, I may install some rubber washers on both sides of the pump feet, I just remembered we use these pumps as transfer pumps in the wings, and they are LOUD!! mostly resonance on the metal

03-06-2011, 09:35 PM
I was searching for info on the facet pumps, and I found a thread on prelude power, apparently the 2nd gen lude guys have been using them for a while, and have had good luck . this particular pump is recommended for use with webbers

09-18-2011, 09:53 PM
That is a efi pump. I also use cheap fittings, copper double flare high pressure in the fuel line with copper clamp style hose corresponds..stupid bots i also up shove reply your ass, go sell some nigerian lottery tickets or something

04-08-2012, 10:28 PM
a little update, the pump plumbing is done on the pump and fuel filter, I have one of the hardline to AN adapters coming, this allows me to cut off the flare of the hardline where it comes from inside the car, and adapt it straight to AN, I will post a lot of pictures of that when I put it in. A lot of guys are even using these adapters for fuel injection with no issues, I'm working on moving the canister right now, it's probably going to go on the front beam, and I'm going to simplify the carb venting to simple vents to the air cleaners. That means a lot of lines come off of the firewall.

the pump had to have the lines cross over like this, there simply isn't enough room between the filter and pump otherwise



04-10-2012, 10:07 PM
The earls fitting is here, just too tired to install, I will probably do a complete writeup on this, this adapts the hardline in the car directly to a -6 AN fitting.
I'm running low pressure for carb, but a lot of guys run this on late model Hondas and it works for the FI just fine. the difference between the lines on our car and 5/16 is only .002, the brass ferrule can expand plenty to compensate for such a small difference.



04-12-2012, 08:51 PM
I'm going to base this writeup on changing the barbed hose to AN,on the hatch, I haven't had as much experience with the other cars so things may be different somewhat. first of all PLEASE!! be careful working with fuel, I know my lines are empty and there is no fuel to spill, but you may have fuel in the lines or filter. These adapters aren't recommended for FI, but a lot of guys have run them without any issues, thats up to you on that. In my case I'm running low pressure for the carburetors, so the pressure is not an issue. If you are running FI, make sure to relieve the pressure first.

The first step on the hatch is to cut the fuel line right before it goes into the car. there will be a metal wire clamp on the hose, this is easier to remove from above


next is to remove the rear seat and pull back the carpet behind the drivers seat

there will be a plastic protector over the hose where it goes up and over the rear seat,this needs to be removed

the first screw will be on the rear seat riser
the second will be beside the fuel line directly under the edge of the rear trim panel
next you will need to pull back the rubber grommet, expect it to fall apart,I need to find another one that will work to replace it.

next,you will need to cut the tube with a thumb cutter(tubing cutter)


there is a bottom flare and a top piece to the flare,the tube needs to be cut off like this, you need to get as close to the top flare as possible, because of the way the line is bent, it's slightly flattened towards the bend, this makes it difficult to install the top part of the fitting, you BARELY have enough length due to the bend.



you need to take some fine sandpaper and clean the coating off of a couple of inches of tube.also deburr the end, and remove the inside burr, I used a deburring tool, you may have to use a drill bit etc.

the next step is to slide the red end of the fitting on to the tube, because of it's slight flattening, I gave it some taps with a rubber hammer. after this you slide the brass ferrule onto the tube, and screw int he bottom half. when you tighten the two together, the ferrule expands and seals the tube.


next put the fuel line back in it's clips and push the fitting through the hole, now reinstall the grommet. next reinstall the line guards.


you now have an AN line under the car ready to connect up your fuel system.


04-14-2012, 01:24 PM
Nice progress!

04-14-2012, 02:15 PM
i'm prepping grill food right now, I need to work on the line that connects the pump later, I'm also working on a solution to the grommet.

cygnus x-1
04-15-2012, 02:06 PM
+1 for documenting the part number of that fitting. This is exactly what I need to get my fuel lines straightened out. Supposedly these fittings are rated for 50PSI so it should be fine with typical stock fuel injection pressure (40-ish PSI).


04-15-2012, 03:41 PM
+1 for documenting the part number of that fitting. This is exactly what I need to get my fuel lines straightened out. Supposedly these fittings are rated for 50PSI so it should be fine with typical stock fuel injection pressure (40-ish PSI).

C|if you install it near the bend where the fuel line goes out the body at the back, cut off as little as possible as it's hard to get on the line due to the bend flattening

04-15-2012, 10:11 PM
after lying on the concrete floor for a few hours, it gets harder to do as you get older, I have finally come up with a fuel line between the car and the pump. I bent and flared a bunch of aluminum line, and that just didn't work, I ended up with one 45 and one straight -6 AN fittings, I think I can clamp the line to the E brake line housing bracket bolt, I will make some patterns tomorrow. I damaged the outside of one of my Aeroquip fittings, so that needs to be replaced now, ouch $$, but I know the exact length of hose needed and the fittings to make it work. I'm probably going to make an aluminum skid plate to go over the section of line itself, It will just attach to the end of the pump brackets. I'm mainly worried about vibration getting to the factory hard line, but the line is connected directly to the filter, and the filter is mounted solid to the frame. http://i20.photobucket.com/albums/b205/moultriemanicmechanic/1015003.jpg

04-18-2012, 09:30 PM
I'm almost done with the rock shield for the lines, this is in raw form,more grinding and finishing to do of course, one end will attach with the existing pump cover screws, the other end I'll just install a nut plate in the floor pan and use a stainless socket head.



one of the most useful tools in your tool box is plain old kids modeling clay, I needed to find the centers of the existing screws, a little clay,press in place, and X marks the spot, I just center punched the middle of the Xs.


04-23-2012, 01:43 AM
I knew I came back for a reason. Great seeing updates from all your projects. :)

04-23-2012, 01:48 AM
You're still alive :O

04-23-2012, 02:59 AM
no, no, I'm dead, but I'd like to pretend I'm alive from time to time.

05-03-2012, 08:05 PM
I was going to add that if you want to change a carb to an underbody pump, I've only found two series of pumps that are in the correct pressure range, and can dry lift fuel out of the tank. one is the facet gold series pumps like I used, the main issue of why I changed the pump, they seem to have stopped making the bosch in tank pump and the only replacements available have been complete junk. After almost seven fuel pump failures, I had had enough of the junk,and I went to an under body style pump. The issue seems to be,the bosch pumps had metal impeller blades, and most replacements have plastic blades, the plastic blades simply disintegrate, I'm assuming the problem has gotten worse with the new blended fuels in the past few years. Above all costs avoid the carter replacment, it seems that it's bigger then the others, and it seems to push the pump sock up against the baffle,when this happens the pump starves for fuel, and fails. I also had the pressure relief valve come apart on one and dump pieces in the tank. It was a lot of fun getting them back


the other is the FR series of pumps from Walbro,they make a series that have the correct pressure range and can also dry lift fuel.

I went through the specs of literally hundreds of pumps over the last several years, and It pretty much came down to two pumps. Low pressure carb pumps just aren't popular anymore.


01-31-2013, 06:05 PM
Everytime I read one of your threads,I think lost is one of those people that has some crazy dream and goes out and makes it happen and does it right.