Lift pump?

[Parker2]

I just found that my lift pump is not running. The truck runs great and gets up to a thrilling 56 mph. My questions are am I going to ruin my injector pump by running without the lift pump? Also has anyone used a civilian inline pump as a lift pump? If so how did that go?

Thanks.

 

[SCSG-G4]

Don't run out of fuel! And, you will have an adventure when it comes to changing the fuel filters.

 

[frodobaggins]

Don't run out of fuel! And, you will have an adventure when it comes to changing the fuel filters.

I ran out. My lift pump doesn't work. I filled the tank and it took about 2 minutes of cranking but it finally cranked.

Now about changing fuel filters, tell me about the adventures ? I need to know !

 

[Recovry4x4]

Filling the fuel cannisters can be a chore without the pump. OD Iron does have an inline pump assy.

 

[KaiserM109]

Carter makes a 24V in-line pump for about $70. I have a dead in-tank pump too, and am considering it. Does anyone have any experience with these?

 

[frodobaggins]

Carter makes a 24V in-line pump for about $70. I have a dead in-tank pump too, and am considering it. Does anyone have any experience with these?

I'm on phone or I'd give you a link.
Try search for "in tank pump" and it's mentioned in several of the larger threads.

 

[Parker2]

I was thinking of going with a Holley (black) or (red). I dont like carter pumps too much. They came stock on my generation Dodge truck. These were prone to fail and in doing so cause the death of a $2,000.00 injection pump.

So no one has come out and said it, but I am getting the idea that running the truck without the lift pump will not hurt the injection pump. Is this right???

Thanks.

 

[SasquatchSanta]

Carter makes a 24V in-line pump for about $70. I have a dead in-tank pump too, and am considering it. Does anyone have any experience with these?

Yes --- I've ran what I call the "thumper" pumps.

I quit using mine and bought a stock in-tank pump from Olympic Controls for approx $250.00 when I realized that the in-line thumper pumps don't put out sufficient flow to keep the fuel pressure in the required 3 to 5 PSI range.

The TMs say for maximum power the IP booster pump needs 3 to 5 PSI pressure. When I installed my fuel pressure gauges I learned that when you start the engine the fuel pressure drops to zero when running the thumper pump. That tells me that the thumper pumps don't have the needed capacity.

With the stock in-tank pump the pressure stays around 5 PSI.

Whether this will eventually harm the injector pump I can't say. I do know that power drops when you're working the engine hard and the in-tank pump isn't pumping.

I've been told that the only thing the in-tank pump is for it to get the engine started. That clearly isn't what the TM says.

I plam of running WMO this summer --- another reason not to run the thumper pump.

 

[M543A2]

We have been running our M543A2 for years with the lift pump shut off in normal driving conditions. I do not use the right hand tank on the truck, so we put the in-tank lift pump on the transfer pump switch. We turn it on for starting, especially in winter, changing filters, and really high power demands. Other than that, we can use the truck normally with the pump switched off with no problems. Given the high cost of the in-tank pumps, we figure why run them all the time when they are not needed. My son had an idea as we were finishing up the large project of getting our 5 ton dump running. He said we ought to rig the accelerator pedal with a micro switch so the in-tank pump kicks in with a certain level of pedal down-travel, which is when high fuel demand is present. To start the truck, or prime the system just push the pedal down to engage the supply pump. An indicator light on the dash will tell us when the pump is energized. We have a good supply of micro switches, so we will try the idea on the dump truck first.
Regards Marti

 

[rainbow]

All you guys looking for intank pumps, take one out of a chevy oar gmc 70series or any truck with a step fuel tank. It is the same pump only it is 12 volt. Run it off one battery when starting, shut it off while running. They are cheap and plentiful in salvage yards. The outlet diameter is slightly smaller on some of them for some reason.

 

[KaiserM109]

… When I installed my fuel pressure gauges I learned that when you start the engine the fuel pressure drops to zero when running the thumper pump. That tells me that the thumper pumps don't have the needed capacity.
…
I plam of running WMO this summer --- another reason not to run the thumper pump.

Where did you put your pressure sensor?
What is WMO?

I drove an M109 overseas and deuces State-side in the 60’s and ‘70’s, but I couldn’t tell you if they were turbos or not. When I drove my non-turbo M109A3 from Ft.Riley, it didn’t perform as well as I expected and occasionally seemed to run rough, particularly on hills with the pedal-to-the-metal. I now think that I was running strictly on the IP and I am guessing the fuel flow was not sufficient.

Common sense tells me that an in-tank pump that pushes all the way instead of one that sucks from the tank and pushes to the IP would be the best. Also one that would run only enough to keep the pressure at the prescribed 3 – 5 PSI (Thanks SasquatchSanta for that info) would save wear and tear.
In searching old threads I found this one: (http://www.steelsoldiers.com/deuce/35412-quit-running-2.html) and the attached pictures:

This is OD irons listing. Looks Easier to install but we know looks can be deceiving

LDT External Fuel Pump Kit$101.13

Finally a drop in solution to replacing defective in tank pumps on LDT and LDS trucks. Simple installation, no hose, clamps, etc simply cut approximately 6.5" from the existing fuel line and install the inline pump in its place using the stock pumps wiring for power. Pump specs... .750 GPM (45GPH) self priming, 24 volts, adapted to 1/2 inch self aligning fittings to fit the fuel line

I know there was another post about another in-line pump that I believe regulated the pressure, but I can’t find it.

As far as running a 12V pump off of 1 battery, that means I have to run a separate wire or cut into an existing one and running an unbalanced load on the batteries just doesn't seem like a good idea.

About damaging the IP by not having another pump, I doubt that will happen, but what about running the engine too lean or with drop-outs in the supply?

 

[SasquatchSanta]

I installed two fuel pressure gauges. The first gauge reads the pressure between the fuel tank pump and the primary fuel filter. The second reads the pressure after the primary filter. I did this so I could determine if a primary filter was starting to ice of plug "hopefully" before it shut the engine down in a place that would be difficult to change the filter.

With a fresh filter there is very little pressure drop across the prinary filter. With the stock Olympic Controls in-tank pump the fuel pressure after the primary filter will sometimes drop down to 3PSI when you're standing on it like on a hard pull.

With the thumper (OD Iron) pump the gauges will register 5 PSI before the engine is started but as soon as you start the engine the pressure drops to zero. In other words, the thumper pump's capacity in insufficient to supply the demands of the IP pump therefore the IP pump is having to suck fuel through the thumper pump.

Whether this is a problem or not I do not know. I ran down to Minnespolis and back a couple of yesrs ago which it approx 550 miles using an OD Iron pump. I was heavily loaded and towed a trailer. I would estimate total gross weight to be 28,000 pounds. The truck performed perfectly fine with the OD Iron pump. If I hadn't installed the twin fuel pressure gauges and therefore noticed the negative fuel pressure when the engine is running I would probably still be running the thumper pump.

WMO = Waste Motor Oil. The viscosity is much heavier than standard diesel fuel. I don not know how how the thumpers would handle/pump WHO. I "think" there are a few people running/pumping 100% WMO with the thumper.

 

[aboonski]

Here's the solution someone used to make the fuel pump run in my truck - for a while anyway... Definitely a bad pump in my tank! Power is there where it needs to be. I am amazed that my truck starts and runs as good as it does! I figured I would check to see if my lift pump was functional prior to changing my filters and sure enough, it isn't. The other day I was over with Lavarok and he just happened to check to see if his M109 pump was operational. When he threw the main switch on I could hear the pump working all the way over by the driver's side of the truck; also, when he took the cap off of the fuel tank you could hear fuel going back into the tank from the return line. After seeing and hearing these things I knew what I would find when I checked my truck.