WMO and Surging

First off let me say that we are traveling and do not have access to many of the things back at Base Camp.

We have just recently done over 400 miles, about 275 of it on dirt tracks, and have been collecting and using WMO as fuel. About 30 miles after one of our "fill ups" the 109 started surging. I've had this happen once before on my m35, changed the primary and was back in action. This time I did a quick filter change out on the side of the road, she fired up . . . and off we went. Maybe, another 20-30 miles and she was doing it again. Did another quick change (we're carrying a few filters of each type that we need . . . and I am getting to be an expert on how to change them), it didn't help! And, the filter looked pretty clean.
I've now also changed both the secondary and the final.
I've also read every thread that I could find about such problems.

What I find odd is not only that Elise's 109 is doing it but not my m35 (We have both trucks and a 105 w/ us), but that if we let the truck sit (some times for only 10 mins) it will fire up and run great. 10, or 20 miles later it starts losing power . . . then surging . . . then finely it will not even idle. She did get oil from a drum that I did not, so I tend to think that it was something that we picked up from that drum. If it's not the filters what could it be? I did run a half gal of oil into a container while I was picking it up and there has been no water separation over the last week. The in-tank pump works. I don't know the pressure but it runs out the draincocks and bleeder like normal. Tomorrow I'll try draining the tank to see if I can find something in there . . . I don't know what else to do check.

I've been filtering the oil through a basket strainer when pick-up pumping and multiple paint strainers on the way into the tank. I've just changed our pump from air power to 24v and added a fuel/water separator w/ spin on filters that have a draincock. Tomorrow should be the first test of this "New & Improved" fuel processing trailer.

But in the mean time what is making the "She Beast" surge and lose power after 20 miles?

Have you checked for water in the fuel? I got some bad wmo once and when I pulled the fuel tank drain plug I got 7gal of water before the fuel started emptying. I agree it sounds fuel related. I'd put a 5gal bucket under the tank and see what comes out.

There has been no water in anything that I've drained from the cans when I changed filters.

If you let it sit for 10min and it starts up fine, then starts acting up again, its got to be a fuel issue. Would a failing hydraulic head do this(I'm not sure)? You could eliminate the fuel as a variable by pumping the tank empty and putting in pump diesel.

Okay, drained about 4 1/2 gals from tank (there's not loads in there right now). It seemed clean. It has been thinned by some gas (at the first fuel station we found after it started doing this . . . it was in the 30's those few days) 5 gal, and later w/ some diesel . . . about 8 gal.
I let the fuel that I drained from the tank sit in the sun for a few hours (SoArizona) then poured it back into the tank through a few layer of paint strainers, saving the last in the bucket. I see no water and very small amounts of grit.
Not even sure where to go from here. And, of course, we have a deadline to get back so that Elise can take some classes that she's signed up (and payed) for.

I realy donT know about the in tank pumps used for the multi fuel, so I am asking, on the in tank pump, is there a INTAKE filter on the pickup before the pump, the reason I ask is on some older trucks that I have had had a FILTER on the drew tube in the tank, this would clog and give me the same problems that you describe

When I got my Deuce it ran crappy, and wouldn't get over about 30 MPH and had no power. After about 30 miles is started to kick and sputter and buck a bit. After trying to bash my head on the back of the cab for a mile it gave out a loud cough and ran fine, It had lots "for a Deuce" of power and climbed rapidly to 55. When I got home I tore into the injection pump and found my fuel adjustment screw "the one everyone turns up" was broken. I am not sure how it even ran. I pulled the whole piece off and welded it back together. Then using a mix of files and emery cloth I got it back to the proper dimensions. It has run fine ever since. I'm not saying this is what has happened to yours but it's what I dealt with.

The in tank pumps have a wire screen around the impellers, I really doubt that is clogged, but its possible. Have you tried opening the fuel tank cap and then blowing pressurized air from the IP fuel line back to the tank? If it isn't a fuel delivery issue, it has to be IP related. What state are you in, maybe someone near you could help trouble shoot.

I have not tried that. Would have to come up w/ some manner of pressured air . . . my truck maybe, . . . would hate to have to do it by mouth, don't like her truck that much
We are in Tucson, AridZona right now, and I know that there are some Tucsonans on the forum. Sure would love that "search members by location" deal right now.

gimpyrobb said:

Have you tried opening the fuel tank cap and then blowing pressurized air from the IP fuel line back to the tank?

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The more I think about this the more confused I am. Do you mean the return line to the tank? Or do you mean from the IP back through all the filters? Or just from the IP back to the final? You said "back to the tank so I'd guess not the last option.

Sounds like you're getting air in your fuel line from a leaky fitting.

Sounds plausible, but when my supply lines rotted and cracked, she ran rough and never would come up to speed.....

Possibly an old and in need of replacement supply line to the fuel filters and the IP? Mine were collapsing from the inside and starving the engine.

Just thoughts...

I was thinking BOTH ways, but a leaking line could do it too.

gimpyrobb said:

I was thinking BOTH ways, but a leaking line could do it too.

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Everybody told me you thought both ways but I never believed them.........I guess they were right.....

G-Force said:

Sounds like you're getting air in your fuel line from a leaky fitting.

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I don't understand how I would get air into the lines. If the fuel system is pressured from the tank pump on why would it not leak out instead of in?
I have pressure through all the filters, out the draincocks and bleeder.

It's not like we haven't used this rig a lot. This summer we did 1500 miles to the Black Rock and back through Death Valley. We did have some filter clogging on that trip, but it was just the basic lose power on grades and such. When we got back I swapped all filters and she was running good again.She also ran great for the first week of this trip . . . till I added fuel (WMO) from a station in Gila Bend. This all started after that.

Gimpy - do you mean to blow out the return line?

After the bad batch of fuel I mentioned earlier, I wasted 2 full sets of filters and drained the fuel tank.

Could a minor amount of water clog up the filter enough to hinder the fuel flow and not show signs in the fuel itself? I think so, but thats me. When I had a batch of fuel with water, I had to let it sit overnight and the next morning, I turned on the power, drained ALL the filter cans of water, and used a bit of ether to get it started. Once it was running it was fine from there on, but getting rid of the water sucked azz.

Might try to swap out the filters again.


To answer about air in the lines, the plastic return lines get brittle from the heat of the motor, age, and vibration. They can crack and let air in your fuel system causing head-aches.

Mine did this, I change filter ect.. ( I had real crappy mixer of fuel b20 gas kerosene and wmo). long short of It had problems with my fuse on top the tank.. fuel some how was getting in to it and makinging intermediate contact till it blew the fuse. I replace the fusey thingy with 1.29 fuse holder..

OK, we borrowed a car and I took Elise back to J-Tree. She had classes that she needed to attend.

Now that I'm back on it, w/o the rush deadline, this is what I've found.
When the rig is running, after start up, I have return lines full of fuel. As soon as I shut off the engine (shutting off the pump does not do it) the return line from the flame heater fills w/ air. This includes the front half of the injector lines (from the "T" for the flame heater) and all the way down to the IP. It does this pretty fast. I can find no leaks of fuel when this line is under pressure w/ fuel. Any thoughts? I do not have the same on mine (ether kit) so I'm not sure if this is normal, I would guess not.
I have not tried driving till it starts acting up and then checking the lines (would have to move the other one and trailer around a lot for that to happen)

At this point I'm thinking that I should just pull all the flame heater lines and put in a couple of plugs. I know that the flame heater won't work if I'm running WMO in her anyway.

Thats what I have done. No need for the pre-heater out there!

gimpyrobb said:

Thats what I have done. No need for the pre-heater out there!

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Hey it freezes out here, it just doesn't rain loads.
I've been starting the "Draggin' " w/ ether. I think that the pump is not turned up at all. Elise's 109 starts w/o any help. She does push me up the hills when we are on pavement.
Mine only only starts good after the first time, before that it's ether and some peddle.

is this a hijack?