003A running issue

[ridinshotgun]

So I have an 003A that is giving me issues while running where it seems to be losing engine power. I think it is a fuel issue, possibly pump related but wanted to see if anyone else might have some insight on diagnosing the issue. The issue is that the engine appears to be losing power and surging. It may run fine for a few minutes and then loses engine power that surges back.

I read through the troubling shooting section in the manual for an engine that lacks power and checked the air filter and fuel filters and strainer. They all appear good and oil pressure seems to be OK. When I shut it down and Try to restart it one of the fuel pumps does not sound like it did prior to this issue showing up. Instead of the hard tick like normal it sounds dull and very quick.

In the service manual it gives instructions on how to check the fuel pressure but other than a normal fuel pressure gauge is there any special adapters I need to hook it to the pump for a test. Want to make sure I have what I need prior to starting the work.

Am I missing anything or does anyone have more insight on my issue or think I am chasing the wrong problem?

Thanks!

 

[Light in the Dark]

Do the pumps look original to the set, or do they appear to have been swapped out? Have you checked your fuel tank for floating trash, or the strainers/filters at the South end of the fuel pumps? How do your supply lines look... any seeping or strange appearance? They could be swelling.

 

[Guyfang]

If the pump runs fast, you are sucking air. That's a sure sign of NO fuel, or sucking air from a leak.

 

[ridinshotgun]

Do the pumps look original to the set, or do they appear to have been swapped out? Have you checked your fuel tank for floating trash, or the strainers/filters at the South end of the fuel pumps? How do your supply lines look... any seeping or strange appearance? They could be swelling.

I don’t see any floating trash in the tank and while I didn’t take the strainer off I drained it and it looked clean and flowed well.

Supply lines are original as are the pumps since I got this straight from the DLA site and it hasn’t been messed with by me. The are fraying but no leakage I can see from them.I did have a small leak on the strainer but I fixed that. I’ll have to look around for some replacement lines. Are the fittings on the pump normal or do I need a special adapter to hook up a fuel pressure tester?

 

[ridinshotgun]

If the pump runs fast, you are sucking air. That's a sure sign of NO fuel, or sucking air from a leak.

Yeah not thinking air. I know what that sound is and this is different and if I switch it over to auxprime and run the sound is different between positions. Air I know as quick and loud. This is not that thrum.

 

[ridinshotgun]

Oh and if I can’t respond it because our internet is going off and on since the cell towers are shutting down due to no fuel.

 

[Guyfang]

If it aint broke, don't fix it. If the lines are not seeping, dripping or squirting, then go on to what your problem is. Then, later, when it runs and you want to feel better, do the lines.

First off, have you tested to see if both E2 and E3 electric pumps are working? Have you pulled the filter/strainers out of ALL three electric pumps? You need to look at the fuel system diagram. The E2 and E3 are in series. That's so if one pump fails, the other will take up the slack. They are special pumps, that allow the passage of fuel, through a dead pump from or to the other working pump. Disconnect the wires to E2 and E3. Place the start switch in the RUN position. Then hook up one or the other, E2 or E3, and listen to the sound. Is it pumping? Then disconnect the wire, and hook up the other. Run or not? Do they run fast? Or start fast and slow down?

 

[Guyfang]

Yeah not thinking air. I know what that sound is and this is different and if I switch it over to auxprime and run the sound is different between positions. Air I know as quick and loud. This is not that thrum.

When you switch to Aux, there is probably nothing hooked up to the Aux inlet. So the pump is going to run slow. If the E2 and E3 are running loud and fast, there is no fuel in them. Try them one at a time.

 

[Ray70]

Small correction above, when you switch to Aux. you are turning on the Aux pump ( unless the tank is nearly full ) the Aux. pump, if not hooked to a fuel source will run very FAST because it's just sucking air.
Now, back to the original problem with it lacking power, does the problem seem worse or happen faster when under a load?
You don't need much fuel pressure to make that machine run, just a few PSI
But , see post #3, You mention up top that one of the pumps is now sounding faster than normal, if you are sucking any air in through cracked / frayed suction lines between the tank and E2 / E3 you will not see a leak, but the air bubbles getting sucked in will cause the engine to surge and sputter at both no load and worse under load. depending on how bad the air leak is you may or may not hear a difference in pump sound.
Also, with the pumps running and engine off, do you hear return fuel trickling back into the tank through the return line from the IP?
As for lines, all the fuel line fittings are 5/16 JIC 37* , equivalent to AN-5 with the exception of the return line from the IP which is #4
In a pinch for test purposes you can also use 5/16 SAE flare, but the flare angle is really not right, but it works.
If you need lines made up you can cut the old crimp ends off and make new lines with hose and clamps, but for the price I just buy them on-line from DiscountHydraulichose.com
Just click on custom hose assemblies, figure the lengths you want, choose one of the 1/4" lines available and choose the 5/16 Female swivel JIC 37* ends and away you go. They will be on your door step in about 3 days.

 

[rickf]

Subscribing because this sounds just like the problem I have with one of mine. You can verify the fuel supply by watching the return line from the injectors to the tank, if there is fuel returning to the tank then fuel supply is good.