In-Line Electric Fuel Pump

[pvkd]

At high altitudes and extreme angles my 1971 109 Series IIa with the 2.25 Liter petrol engine has difficulty getting fuel. It has been suggested that I install an in-line electric fuel pump between the fuel tank and the mechanical pump. Does anybody have any experience with this installation?

• Which pump works best with my engine?
• I have heard one only needs the electric pump at high altitudes and extreme angles, so I want to turn it on when I need it and off when I do not. How is it installed?
• Can the mechanical pump pull fuel through the electric pump once the electric pump is off?

Thanks

[4flattires]

While I am not a hydraulic engineer....

I am pretty sure liquid is not affected by altitude (within normal limits) between a mech or elec fuel pump and thus your problem with fuel delivery is due to extreme angles.

You're elec fuel pump will pick up fuel in the same spot in the tank and will still run dry. Yes, a elec can feed your mech. Always place the elec as close to the fuel supply due to the fact they pump well, not draw well.

To test if you mech pump can be "pumped through" while not operating, it would fairly easy to rig up some air hose lines and using very low pressure test your theory. My guess = yes. Mech pumps have one way check valves that prevent drain back, but would allow push through.

Keeping more fuel in the tank sounds like a free remedy.

Jeff

[BackInA88]

Keeping more fuel in the tank sounds like a free remedy.

Jeff

It may not be the fuel level in your tank but the fuel level in your carb.
Have you checked your float level?

Steve

[thixon]

The extreme angle problem has to do with the carb, not the pump. At extreme angles, the float cant function as it was designed to (its made to float straight up, opening the needle valve). This can cause a starvation of fuel, or a complete lack of fuel. All carbs suffer from this problem, with an exception or two. Holley makes a carb called the truck avenger that somewhat fixes the issue, but they are only made for large american engines (as far as I know). The only way to completely solve the problem is to go with fuel injection.

Anyway I'd check the float level, just to make sure its not set low. If everything is as it should be, don't adjust it up for heck of it. The carb won't function properly if you do. Also check the float bowl for trash.

As for the altitude issue, is the truck starving for fuel, or just running poorly? At higher altitudes, without changing out jets, the truck will run rich. You will notice a lack of power, etc. if this is the case. Maybe a seperate issue?

my two cents.

Travis
'66 IIa 88"

[yorker]

How high are the altitudes? are you sure you aren't getting vapor lock? My brother was offroading with a Cruiser club in Colorado Springs earlier this year and one of the rigs went down because of that, you could see the fuel boiling in the fuel bowl on the carb through the sight glass. A low carburetor float level can aggravate a vapor lock condition.

I'd bypass the mechanical pump and run a quality electric one, route the fuel lines to minimize their exposure to heat. I've run an electric pump for 10 years or so and only had one failure in that time. Mount the fuel pump low along a frame rail if you can, I mounted mine higher for easier access and protection but it can make for some issues with drawing fuel, I've not had these issues but others have.

Some systems use a small return fuel line to help control vapor and fuel pressure. The line returns some of the gasoline and vapor to the fuel tank so it will not absorb too much heat while waiting to be used by the carburetor, If your carb doesn't have a return line there is an inline fuel filter from a Dodge application that has a return line built into the filter- someone here might know the part #. I know several people who have used one of these with success.

Aen electric fuel pump that can deliver 4-6psi should work well, I honestly can't remember what model I use otherwise I'd give you the part #. A fuel pressure regulator can be used but may not be needed.

[gudjeon]

Howdy pvkd,

I used a Napa aftermarket leccy fuel pump made for carburetted engines. I mounted mine out of harms way on the RH bulkhead. No probs with suction here. I once had one mounted on the rad shroud and it had no probs too. The bypass fuel filter is one that is generic to chrysler products of the 80's. The bypass orfice lets out a small amount of fuel so onlt so much pressure can biuld. Once shut down, it lets out remaining pressure off the needle and seat. Checky out my setup. You can see the gold coloured pump to the left of my pic. I made a return fitting similar to the original intake. a piece of 1/4" brake tubing curved to a 90degree and made a flange from 1/8" steel. Soldered it together and the hard part is done. I went through a couple of mechanical pumps and would never go back. No vapour lock and no hard hot starting.

I know I have a wierd intake elbow. Its a 2.25 in a series 1 - there is clearance issues under the hood. Ugly, but it works.

[pvkd]

Thanks everybody for the colective wisdom.

You maybe correct that my issue is carb related rather than pump related. Maybe the steep angle and the altitude combined produce the problem which may not be solved by an electrical fuel pump.

At extream angles and altitude the vehicle looses power and has difficult making over obsticles. I need to keep the revs way up and hope that I make it over before the power dies.

Some people talk about a fuel return. I do not have one of these in my standard set up. I don't undestand how this would help me?

Thanks,


Paul

[Grover73]

Electric Fuel Pump

I have had the same problems with my truck. Drove from CT to the MAR in VA and held 70 mph on the highway only to stall out on every little hill in the woods. I cut the fuel lines and plumbed in a electric pump and never looked back. I solved my vapor lock problems, stalling on side angles and on up hills. I have also put electric pumps in three other trucks with the same results. I'm running a 3-5 psi pump and I works just fine with no return. Buy yourself a electric pump, get rid of the mech one, and say goodbye to your problems.

Cheers, Ryan

[scott]

my buddy badvies is looking at a propane conversion, actually a system that will allow switching from propane to petro and back. his reasoning is cost of fuel and cleaner burning (propane). a secondary benefit is propane will work at any angle (no carb float issues)

[yorker]

Some people talk about a fuel return. I do not have one of these in my standard set up. I don't undestand how this would help me?

it helps keep the fuel cooler to avoid vaporlock.

[pvkd]

I cut the fuel lines and plumbed in a electric pump and never looked back. I solved my vapor lock problems, stalling on side angles and on up hills. I have also put electric pumps in three other trucks with the same results. I'm running a 3-5 psi pump and I works just fine with no return.

Ryan,

What pump do you recommend? Do you have a part number?

Thanks,

Paul

[ajones]

Also, do you run the elec. pump in lieu of mech. pump or in series or in parallel? If you don't use the mech. pump do you leave it in place or remove it. If removed how do you blank off the opening?
Thanks.

[gudjeon]

Howdy Ajones,

For my set up, I replaced the mechanical pump for a leccy one. I removed the mechanical one and made a small blanking plate from 1/8" plate. Gasket to fit and done. I went with the return system as I found my particular pump left residual pressure when shut off. When it was warm out, this coupled with the flexing of the fuel lines, flooded it silly. With the bypass filter set up, no more flooding and no v/lock. I know its working every time I start up because I can hear the pump ticking away.

[Grover73]

Fuel Pumps

PVKD - Every time i have bought a electric fuel pump I've just walked into the auto store and asked for a generic low pressure electric fuel pump. Don't try this at a BIG box auto store as you will just get that dear in the headlights look and the "year, make, model?" response. I have run a high pressure pump before but saw no added benefit.

Ajones - Right now I still have the mech pump bolted to the block covering the hole. I run just the electric pump as I find the rover is a very simple thing and it likes to stay that way. I have it mounted to the frame rail under the passengers seat with the fuel filter right before it. I can very easily access this through the middle seat panel and it also keeps the fuel filter cooler. The power for the pump comes off a switched wire in the fuse block. I also have a switch so I can shut the pump off and still have the key on.


Years ago I had a nice little plate that would cover the hole for the fuel pump. When I rebuilt my engine I decided to try the mech pump again. Wish I had never taken that plate off, now I can't find it!!!! But a cover plate would be easy to make.

Cheers, Ryan

[yorker]

Don't forget to plumb a filter in before the pump. It may save you some headaches down the road. I'd leave the stock mechanical pump on the engine, it isn't hurting anything and IF it still works it may help you get home some day if your electric one fails... and they DO fail.