Low pressure EFI pump

[rulebreaker]

I've had issue's getting fuel from my fuel tanks for years. I've tried using just the front tank or just the rear. I've used different pumps both electric and mechanical. I've replaced the sending units the lines the filters and I still have issues. Right now I have a stock fuel pump supplying fuel to my BC Bronco's accumulator and a EFI pump that draws from that and it works great on the flat however on a steep hillclimb the stock pump will loose it's prime despite fuel level and the engine will die. If I blow in the fuel tank and have someone roll it over it will start back up. So I've been pondering buying a 23 gallon EFI tank but that's just too much money. So I pulled a low pressure pump out of a BroncoII and mounted it to my rear tank sending unit.

Will this work? Any idea's on how to run the wiring? I thought about running the wiring up through the filler neck and out but it would be allot easier to service if I run them out with the fuel sending wiring but I dont know the best way to do it. I still dont understand how the gas dont short it all out as the wiring is bare where it connects to the pump. Any thoughts? RB http://rides.webshots.com/photo/2583601850040927262oeugfG

 

[jr]

Does your return line go straight back to the tanks or accumulator? Sounds like your LP pump is not keeping up to fill accumulator. You might want to try just running the HP pump from the tank with no accumulator?

 

[SaddleUp]

My suggestion would be to try simplifying things as mentioned above and just run a single high pressure pump somewhere near the tank with a filter both before and after the pump.

 

[welndmn]

Dump the Accumalator, and see if its better.
What tanks do you currently have? Stock?

 

[COBlu77]

X4 dump the accumulator and just run 1 HP pump as close to the tank as you can get it. I had nothing but problems when I tried to go that way. BTW, I've been running one HP Walbro pump for 2 years now with zero issues. No fuel starvation on hills. It runs until the tank is nearly dry (found out the hard way).

 

[rulebreaker]

Does your return line go straight back to the tanks or accumulator? Sounds like your LP pump is not keeping up to fill accumulator. You might want to try just running the HP pump from the tank with no accumulator?

Right now it goes to the accumulator but I havent always had the accumulator as I started out with the HP pump back by the tank. The only way I see the HP pump working back by the tank is if I can mount it lower than the pickup and there is no way it will servive as the skid plate and tank are looki'n like rock rash right now. At one time I had the HP pump mounted above the rear tank with a low pressure pump feeding it and that would work till I got down to a half tank or so. I thought it was the sending unit so I replaced it, no change. I have had it every consevable way possible and the way it is now has worked the best. I have considered building a skid plate with a spot built in for an EFI pump, maybe I need to try that. RB

 

[rulebreaker]

Dump the Accumalator, and see if its better.
What tanks do you currently have? Stock?

Dual stock tanks but I'm just trying to get it to run off the rear for now. RB

 

[SaddleUp]

It doesn't need to be below the pickup to work. Mine is mounted above the frame just under the drivers seat. It was done that way to get it close to the auxilary tank when I was using one and I've just never bothered to move it closer to the main tank after I pulled it. It's been this way for 3 or 4 years (ever since I first put the EFI in) and I have never had any problems with loss of pressure on steep hills. (It doesn't get much steeper than this)

 

[jr]

Right now it goes to the accumulator but I havent always had the accumulator as I started out with the HP pump back by the tank. The only way I see the HP pump working back by the tank is if I can mount it lower than the pickup and there is no way it will servive as the skid plate and tank are looki'n like rock rash right now. At one time I had the HP pump mounted above the rear tank with a low pressure pump feeding it and that would work till I got down to a half tank or so. I thought it was the sending unit so I replaced it, no change. I have had it every consevable way possible and the way it is now has worked the best. I have considered building a skid plate with a spot built in for an EFI pump, maybe I need to try that. RB

Just mount the HP on the cross member above the rear diff and you should be fine. I saw a few that had the HP below the driver's seat and worked real well. In both cases, they were above the tanks.

Oops saddleup is a faster typer than me

 

[rulebreaker]

It doesn't need to be below the pickup to work. Mine is mounted above the frame just under the drivers seat. It was done that way to get it close to the auxilary tank when I was using one and I've just never bothered to move it closer to the main tank after I pulled it. It's been this way for 3 or 4 years (ever since I first put the EFI in) and I have never had any problems with loss of pressure on steep hills. (It doesn't get much steeper than this)

I'll try it again but if it didn't work before I dont see it working now. RB

 

[SaddleUp]

I'll try it again but if it didn't work before I dont see it working now. RB

If I read everything correctly above when you tried it before there was a low pressure pump in the system before the high pressure one. If so then that may be what was causing the problem.

 

[welndmn]

Ok, I think its a Tank issue then.
The stock tanks don't have a lot of baffles, and once you get low on fuel, it runs away from the pickup hole.
Go look at that rear tank and see if what I am thinking could be the problem.
It was a long time ago I had a stock tank.
In your first post, you said "Stock pump" are you using a mech pump on the engine?
If so stop, you can't as the mech pump can't be "sucked through". Either run the small pusher pump, or none at all.

 

[70EB]

X4 dump the accumulator and just run 1 HP pump as close to the tank as you can get it. I had nothing but problems when I tried to go that way. BTW, I've been running one HP Walbro pump for 2 years now with zero issues. No fuel starvation on hills. It runs until the tank is nearly dry (found out the hard way).

Which Walbro pump are you running? I have the MSD HP pump that I think may be a little underpowered with the 351W and 24lb injectors.

 

[bmc69]

Odd..it seems like yr having problems with a setup that is identical to mine and I have had no problems at all.. and at even the most extreme angles with less than a quarter tank of gas.

408 EFI. The stock mechanical pump runs to the accumulator/filter which has a return to tank. My HP pump is mounted just next to, and slightly below, my accumulator/filter and the EFI return line tees in to the return line running from the accumulator/filter to tank.

All same, right?...can't figure why yrs would be having a problem with the mechanical pump loosing prime..the vacuum suction produced by a diaphragm fuel pump is way more than that produced by an electric pump.

Guess I'll count myself lucky since it appears that more than one person has had similar problems to yours.?:?

 

[supachop]

Odd..it seems like yr having problems with a setup that is identical to mine and I have had no problems at all.. and at even the most extreme angles with less than a quarter tank of gas.

Mine is practically the same, but I have a low pressure pump at my rear and aux tanks. I run the return to my electric switch that automatically sends it to the tank it's pulling from. My tank switch also sends juice to the appropriate pusher pump.

I've had no problems with starvation, and the accumulator fed high pressure pump works great at high angles. The only problem I ever had was running only one pusher pump for both tanks. It prematurely cr@pped out because of the long pull from the tanks. The tank specific low pressure pumps seemed to fix my situation.

 

[rulebreaker]

I put an LTD 302 EFI in this truck like 7-8 years ago. I put an electric puller pump by the drivers seat that pulled fuel from either tank and it fed a Ford F250 HP pump. At first the timing wouldn't advance and after about a year off eliminating possibilities I discovered I had mounted the computer up side down. Fixed that and then the Fuel starvation thing started and it took me a while to figure out that it was fuel related. About that time I put a rod through the side of the block. Bought another 302 with 40,000 miles that lived a very short life all the while fighting the fuel problem. I eliminated the dual tank setup and mounted the 2 pumps back by the tank with no change. Advance warrentied both pumps, with no change. So I eliminated the sucker pump with no go.Changed the sending unit, no change. About that time I put in the 351W EFI and the problem remained.I destroyed the C4 and put in the NP435. I bought the accumulator, moved the HP pump up front and put the sucker pump out back. Problem was worse. 3 years ago I eliminated the sucker pump and used a stock block mounted pump. Worked great for about a year or so then My wife and I went to turtle ridge ORV park and talked them into letting us go in alone. We got all the way to the back of the park and were trying to climb the back ridge (It was raining) and it quit. I pulled the accumulator filter and it was dry. I pulled the fuel pump thinking it was bad but thought I would try and pump it by hand as I was desperate. I got fuel. 2 hours later it was back together and drove out thinking it was just a fluke. Went back after lunch and was trying to climb a rock wall and it happened again just as I blew the powersteering hose. I put my mouth on the filler hose and blew as my wife rolled the engine and it started. Put it on the trailer put it in storage(over a year ago) till this week. I built an 89 BroncoII to wheel and basically said to heck with the Bronco. The guy storing it told me to come get it, so I thought I would give it another round. I have 5 kids now and neither truck will work so I'm building an aerostar van to wheel with the family, I'm parting out the BroncoII (using some parts on the aerostar) so I thought it would be nice to get the Bronco running for those times i go by myself. Plus I need something to drive while I build the aero and part out the BroncoII. Once the aero is done I'm going to go to work on the body as she has seen 10 years of hard wheeling and needs some TLC. I'm really tired of the fuel problem and hope to put it to bed once and for all. RB

 

[rulebreaker]

408 EFI. The stock mechanical pump runs to the accumulator/filter which has a return to tank. My HP pump is mounted just next to, and slightly below, my accumulator/filter and the EFI return line tees in to the return line running from the accumulator/filter to tank.

All same, right?...[/QUOTE]Yes all the same. RB

 

[rulebreaker]

Odd..it seems like yr having problems with a setup that is identical to mine and I have had no problems at all.. and at even the most extreme angles with less than a quarter tank of gas.

Mine is practically the same, but I have a low pressure pump at my rear and aux tanks. I run the return to my electric switch that automatically sends it to the tank it's pulling from. My tank switch also sends juice to the appropriate pusher pump.

I've had no problems with starvation, and the accumulator fed high pressure pump works great at high angles. The only problem I ever had was running only one pusher pump for both tanks. It prematurely cr@pped out because of the long pull from the tanks. The tank specific low pressure pumps seemed to fix my situation.

This is why I was thinking of running a Ford in tank supply pump designed to feed my Ford HP pump. How could I go wrong then? Other than blow myself up? The only prolem I can forsee is the lack of in tank baffles. Maybe I need to buy a 23 gallon EFI tank and be done with it. I just don't see myself spending the money to do that, I'm Dutch. RB

 

[SaddleUp]

This is why I was thinking of running a Ford in tank supply pump designed to feed my Ford HP pump. How could I go wrong then? Other than blow myself up? The only prolem I can forsee is the lack of in tank baffles. Maybe I need to buy a 23 gallon EFI tank and be done with it. I just don't see myself spending the money to do that, I'm Dutch. RB

The stock ford system does indeed use low and high pressure pumps. It also has an automatic accumulator/feed/return switch that is activated by pressure from the low pressure pumps. I have one in the garage I considered using about 3 years ago when I had dual tanks but I never got around to putting it in. Since I've never had any of the issues I see posted here by many I just can't see any reason to complicate it. (KISS principle) I've actually set up 4 different rigs now with just a single high pressure pump and 3 of them have been tested at extreme angles. (The 4th. has only been used for mild trails and drives around town)

 

[jr]

Saddleup,

You need to show that video of you climbing that steep hill. Maybe they will be convinced after that.