24v fuel pump and regulator

[pinzinator]

I finally got around to installing an electric fuel pump and regulator. The mechanical pump was OK, I just didn't like cranking the engine to build up fuel pressure whenever the truck sat for a long time, which is often. I did some research on parts and will share all of that.



I started out with a 24 volt Facet fuel pump, part # FAC480564, rated at 4-6 PSI and includes a check valve. The pressure regulator is a Holley unit, part number 12-804, and can be adjusted to 1-4 PSI.





Next, I fabricated a piece of 1/8" aluminum to mount both devices on. The only place this would fit is where the original fuel pump went, which makes sense.



I tapped out the mounting holes so screws would hold it in place. Metric bolts hold the plate in place where the fuel pump used to be. I left the tappet spacer in place to get maximum vertical height.
It was a very tight fit, and it took several tries with variations in plate size and hole location before I got it right.





Final installation. I used 2-NPT 1/4 X 1/4 barb elbow fittings on the pump, and 3-NPT 3/8 X 1/4 barb elbow fittings on the pressure regulator. I also changed the bango fittings on the carbs so each carb had its own fuel line and could use 1/4 inch fuel line along with the rest of the upgrade. I had problems with fuel leaks at the fittings, and used a little pipe dope (minimal) to end that. Teflon tape and silicone sealer cannot be used since it will cause future issues with the carbs.



This is the carb inlet side showing the pressure gauge temporarily connected so I could set the pressure at 2.5 PSI per Jim's recommendation.



The float level checked out OK on both carbs. Then I synchronized the carbs and put everything back together. The Pinz runs great and the new fuel pump has no trouble keeping up with engine fuel demands during hard acceleration and high speeds. I made the electrical connection at the fuel stop solenoid wiring harness.

[Jimm391730]

Do you have any kind of "rollover" protection that will disable the fuel pump in the event that the truck is not upright? This became a necessity once electric pumps became the norm. With the stock mechanical pump, a rollover would allow the engine to die, and no more fuel is pumped. With the electric pump, fuel keeps flowing and can leak down and cause a fire. Or, in lieu of a rollover switch, power should only be supplied to the pump when the engine is running (best done with an automatic device).

[GenevaPinz]

Do you have any kind of "rollover" protection that will disable the fuel pump in the event that the truck is not upright? This became a necessity once electric pumps became the norm. With the stock mechanical pump, a rollover would allow the engine to die, and no more fuel is pumped. With the electric pump, fuel keeps flowing and can leak down and cause a fire. Or, in lieu of a rollover switch, power should only be supplied to the pump when the engine is running (best done with an automatic device).

Good idea. But on a full rollover (truck upside down), and thinking out loud, wouldn't the pump starve at the tank pickup point which would be above the fuel level? It doesn't solve the more probable occurence of the truck being on its side though... what do you think?

[undysworld]

A guy I knew got burned up trapped under a tractor that went up in flames. Better safe than sorry, especially when it comes to gasoline and hot engines and electrical stuff.

Besides, if Jimm recommended it and it's electrical, I'd probably follow his advice.

[Jimm391730]

...on a full rollover (truck upside down), and thinking out loud, wouldn't the pump starve at the tank pickup point which would be above the fuel level?

Yup, I thought of that; but as you mentioned, if the tank is mostly full and the truck is NOT perfectly upside down then fuel will still be pumped. You found the one instance where the rollover switch wouldn't be of great value.

When I went to buy a tall extension ladder, I spent the extra money to get a fiberglass ladder -- my reasoning was that if it was made with aluminum, and it started to fall towards overhead power lines I didn't want my last thought to be "oh, $hit, I wish I had spent the extra $50 to get a fiberglass ladder!" If you can think of drastic situations that can be alleviated with a bit more thought (and sometimes a bit more $), wouldn't you do so?

I, too, had a friend that perished in an ultralight aircraft accident where it overturned on landing and he died in the fire.

[kdiqq]

Coming from the motorcycle world, nearly all EFI bikes have a rollover sensor. I bet you could repurpose one pretty easily and cheap!

[pinzinator]

Once again, Jim is absolutely right. I did a Google search and found quite a few inertia switches available online, which I assume are also rollover switches. I'll have to research that a little more.

[Texas710]

"I just didn't like cranking the engine to build up fuel pressure whenever the truck sat for a long time, which is often." (sorry, have not learned to quote yet)

This. This has been on my mind lately. Is there another way to not have to deal with that issue? I am thinking like a foot valve, or check valve. I was even thinking some sort of primer bulb setup, like on an outboard.

I am okay with trying the fuel pump, but the whole keeps pumping even if truck is on its side thing is sort of throwing me off. Would like to know if you get that detail sorted.

Just the little things you know.

[63rover]

The fuel isn't draining back. It's evaporating. I had some older vehicles that had manual prime levers for just that problem. Has anyone heard of a pump with a lever that would fit? My truck runs into this problem too in about three or four days between the summer heat and living in it's shipping container garage.

[krick3tt]

I would think that the lever to prime a fuel pump would be an issue on a Pinzgauer as the engine cover might have to be removed to access the lever. Most other civilian or military vehicles have access to the engine bay via a bonnet or other easily lifted device.

It is a great idea though and would solve some issues, especially evaporation. I find the gear reduction starter I installed does a great job turning the engine to get the pump supplying fuel to the bowls.

[TechMOGogy]

Not to hijack this thread but... that shipping container garage rocks!

[edzz]

Not to hijack this thread but... that shipping container garage rocks!

tic - needs rub rails.

[rmel]

I don't know if this particular pump and setup will be problematic,
but I found the "dry lift" spec's are not to be fully trusted as a matter
of course for day in day out operation. For this pump, spec is 12" lift,
where you are mounted your in that ballpark -- definitely above the
fuel level so you will be dry lifting any time the system drains of fuel.
Problem is pump wear out if each and every cycle is a dry lift event,
the fuel is the lub.

Built in valves are really designed to operate under pressure and are
not check valves per se, any checking when the pump is "off" would
require the pump to be mounted vertically otherwise they leak fast.
Even vertically they will leak pretty darn quick, minuets.

I learned this the hard way blowing through 2 very expensive Pierburg
high pressure fuel pumps albeit this is a fuel injected setup so different.

I ended up mounting the pump on the firewall as low as possible, which
is a tad below the fuel level of the tank when full, thus lower levels of
dry lift vacuum is required. I also added a high performance check valve
to hold fuel in the system when the pump is off for extended periods of
time. This valve is spec'd at fractional "drops" of leakage per hour, metal
flapper and mucho expensive.

[pinzinator]

I have had no problems at all, the Pinzgauer runs great at all speeds. What I like the most is starting the engine- turn on the key for about 5 seconds, pump it once, and it fires right up without stalling. This is the same engine that used to stall at least twice, and I had to keep pumping it like a 70s truck to keep it going the first few seconds. No more!

[Texas710]

I should say, BTW, great looking modification and write up. I am glad to know that the truck runs good on this set up, I will probably be picking your brain about this in the future.

I think this is getting on the "to do list" just maybe not the "to do tomorrow list"

And that shipping container is super cool.