FLU419 won't start. need help!

[majkowskid]

good evening everyone... a little background. my brother sold me his 419 that he had sitting for 7-8 years. around 60 miles on it and VERY low run hours. like 15 hours, seriously.

when i went to pick it up, it started right up after fixing a wire rats got to. i have been running fuel through it at my ranch and put around 30 miles on it just pushing brush piles. i was going to remove a boom cylinder this weekend to reseal, but the mog died on me when moving it around. it will crank, and idle occassionally VERY rough. a little shot of starting fluid and the engine runs great for 2 seconds. it's quite obviously starving for fuel. i decided to drain all the old fuel out, and put new in. checked the fuel strainer and it was clean. i have had fuel filters ordered for a couple weeks but they aren't here yet but i decided to check them anyways. the filters have a stamped date of 09-08-52 on them. seriously! they seem ok honestly.. but are obviously old. i put them back in, and blew low pressure air through the fuel lines from the tank. I then used the primer to reprime which was a helluva ordeal. i was pumping that stock primer pump for like 30 min. it started and ran like it was aobut to die for 5 min. i just let it sit there and try to idle, and all of a sudden it cleared up. i drove it for 2-3 min, and then it just lost power and died again. i can't get it to start now. i tried to reprime the filters and no fuel would come out after 10 min of pumping.

1. i'm waiting on the new filters and seals and will put them in when they arrive.
2. i ordered the new design primer from expedition imports.

could it be the actual primer assembly? i'm praying it's not the actual fuel pump assembly as it looks pricey.

 

[Mullaney]

good evening everyone... a little background. my brother sold me his 419 that he had sitting for 7-8 years. around 60 miles on it and VERY low run hours. like 15 hours, seriously.

when i went to pick it up, it started right up after fixing a wire rats got to. i have been running fuel through it at my ranch and put around 30 miles on it just pushing brush piles. i was going to remove a boom cylinder this weekend to reseal, but the mog died on me when moving it around. it will crank, and idle occassionally VERY rough. a little shot of starting fluid and the engine runs great for 2 seconds. it's quite obviously starving for fuel. i decided to drain all the old fuel out, and put new in. checked the fuel strainer and it was clean. i have had fuel filters ordered for a couple weeks but they aren't here yet but i decided to check them anyways. the filters have a stamped date of 09-08-52 on them. seriously! they seem ok honestly.. but are obviously old. i put them back in, and blew low pressure air through the fuel lines from the tank. I then used the primer to reprime which was a helluva ordeal. i was pumping that stock primer pump for like 30 min. it started and ran like it was aobut to die for 5 min. i just let it sit there and try to idle, and all of a sudden it cleared up. i drove it for 2-3 min, and then it just lost power and died again. i can't get it to start now. i tried to reprime the filters and no fuel would come out after 10 min of pumping.

1. i'm waiting on the new filters and seals and will put them in when they arrive.
2. i ordered the new design primer from expedition imports.

could it be the actual primer assembly? i'm praying it's not the actual fuel pump assembly as it looks pricey.

.
Chances are that replacing the fuel filters will resolve the problem...

.

 

[peakbagger]

good evening everyone... a little background. my brother sold me his 419 that he had sitting for 7-8 years. around 60 miles on it and VERY low run hours. like 15 hours, seriously.

when i went to pick it up, it started right up after fixing a wire rats got to. i have been running fuel through it at my ranch and put around 30 miles on it just pushing brush piles. i was going to remove a boom cylinder this weekend to reseal, but the mog died on me when moving it around. it will crank, and idle occassionally VERY rough. a little shot of starting fluid and the engine runs great for 2 seconds. it's quite obviously starving for fuel. i decided to drain all the old fuel out, and put new in. checked the fuel strainer and it was clean. i have had fuel filters ordered for a couple weeks but they aren't here yet but i decided to check them anyways. the filters have a stamped date of 09-08-52 on them. seriously! they seem ok honestly.. but are obviously old. i put them back in, and blew low pressure air through the fuel lines from the tank. I then used the primer to reprime which was a helluva ordeal. i was pumping that stock primer pump for like 30 min. it started and ran like it was aobut to die for 5 min. i just let it sit there and try to idle, and all of a sudden it cleared up. i drove it for 2-3 min, and then it just lost power and died again. i can't get it to start now. i tried to reprime the filters and no fuel would come out after 10 min of pumping.

1. i'm waiting on the new filters and seals and will put them in when they arrive.
2. i ordered the new design primer from expedition imports.

could it be the actual primer assembly? i'm praying it's not the actual fuel pump assembly as it looks pricey.

My guess is you have an air leak in the vacuum side of the fuel system. Its a known issue. What sometimes works is use the trick I learned on the internet about leaky plastic mercedes fuel lines which is cut a piece of fuel hose whose inner diameter is the outer diameter of the plastic fuel hose. I cut them the lenght of the mercedes fuel line barb and slit them lengthwise and slip them over the plastic tubing at the hose barb. I then put a screw on hose clamp over the fuel tubing and cranked it down. Ideally, I should have used a smooth fuel injection clamp on the hose but the screw type with the slots worked. This may not work but it is important to the next stage since the fuel system including the injection pump and injectors are full of air. You can pressurize the tubing and the leak may not show but put it under vacuum and it will leak just a bit. Once you pull enough air through the system you are "screwed" and its on to the next part of the fix.

Mine had the same issue and how I finally got it to go may sound bizarre, but it worked a couple of times. You need a fuel tank from a small outboard motor with a squeeze bulb. I didnt have a boat so I bought a plastic version on sale at a boat supply store. Then after confirming that the two final fuel filters were clear I disconnected the steel fuel line downstream of the fuel strainer down on the frame rail. I slid back the nut on the tube fitting and slipped my hose over the end of the fuel line and sealed it with a hose clamp. I filled up the tank with diesel and set it higher than the fuel rail (I set it up on the passenger seat but if I had enough hose I would put it on topf of the FOPS (military speak for roof over cab). I cracked the fuel bleeder on the final filters to get the air out and then pumped the squeeze bulb until I felt pressure. I then got in and it started up. It didn't run well initially but it did start. I just kept pumping the squeeze bulb and it started running fine. I then shut it down and hooked the tubing back to the strainer and it started up. Note, buy a fuel strainer gasket while you are at it, they get old and leak and it is the low point of the system. Crap in the fuel tank will sometime let loose and plug the strainer so make sure it is not plugged.

A few years later I learned that there is a internal pressure relief valve in the injector pump. When that opens there should be fuel in all the injectors. Normally this is held shut with a spring and the pump stays flooded but I park mine over the winter and the fuel always drains out the injectors. I also installed the new style Bosch primer pump. The local Unimog expert suggested pumping this pump multiple times until I felt pressure and keep pumping until I hear a "wheeze/squirt" up near the pump. You need to be in quiet area but in the spring after sitting 4 or 5 months when I pump it 40 to 60 times and am about ready to give up, I hear the "wheeze/squirt" and then I hop in and it starts right up and turns over in just a couple of revolutions until I park it in the fall. No need for the boat tank for two years using this method. So the fix is a mix of two things get rid of any vacuum leaks and then completely prime the system (far more than the manual indicates).

BTW, a dose of Power Service diesel injector cleaner for a few tanks is good ideal if its been sitting. My Unimog friend just cleans/changes the final filters and fills them with straight injector cleaner when he buys them at auctions and hand primes with the primer pump until he hears the squirt. In some cases folks on this board have found some nasty slime/gunk in the fuel tank that may be biological in nature, do what you need to to get the tank clean. BTW the fuel system circulates fuel from the injector relief valve back to the tank to cool it so if you run off the boat tank to get it back to the barn make sure the tank is connected or you will be pumping diesel onto the ground.

Good luck.

 

[BELinNC]

I think the majority of FLU419 owners have chased air leaks in the fuel system. When I got my most recent one it had the same issue. I changed the main filters, the prefilter and would bleed the air out and it would run for a couple minutes and die again, I thought the next most likely culprit for air leak was the priming pump so I got the new style from EI and same thing, although it would pump for the bleeding process much stronger than the original one. Was getting very frustrating! Turns out my problem was the short flexible lines at the top of the fuel tank that connect the supply line and return line to the hard lines. They are a bit hard to get to, but the one to the supply line that heads to the pre filter had failed and was admitting air to the fuel system. Was a pretty easy fix to replace them and since then mine starts about instantly even after sitting for a week or two. So you might want to check them on yours. Good luck

 

[majkowskid]

Thanks for the help everyone!
I’m going insane trying to get this back running. It was running perfect after not being started for 7-8 years and then after 20 miles it’s killing me!
I replaced the primer with the new Bosch model and no luck. I have found that the gasket in the fuel tank cap was boogered up. Could this cause the issue? I just ordered a new one. Waiting on new fuel filters, new gaskets for pre sediment filter and main filters.

I think I’m going to run new fuel lines just to rule them out. Does anyone know if 1/4” line will fit? It looks like 1/4 but someone told me it’s 7mm which is hard to find.

 

[The FLU farm]

I chased several air leaks, and severe bacteria in the tank, for a while.

BioBor took care of the bacteria and parts and pieces from Matt (of course I can't remember the company name now) solved the air leaks.

 

[peakbagger]

Back in high school I would occasionally have to get crap boxes running. With a gas engine the questions were, does it have fuel, ignition and would it turn over. We didnt have money to burn, so before going any further, we unscrewed a plug and laid it on the manifold and looked for a spark, then we looked down in the carb and looked for gas squirting out the jets. Next thing was pour some gas down the carb and so it if started. If it stayed running we went in another direction but if it stalled then we rigged up gear oil bottle full of gas to the fuel line and squeezed the bottle to feed fuel to the carb. If it kept running than it was a problem with the fuel system. In the case of the SEE, no ignition so skip to fuel. Crap in the fuel tank, dirty strainers , leaky gas lines , bad fuel pump and dirty filters are all great to work on but I would rather triage the problem and get it running off a temporary fuel system then work my way back on why its not getting fuel.

The injection pump is the highest point in the fuel system and it can trap air. It just needs to be flooded with fuel and that means no air can be in it. The boat tank method or something similar gets rid of all the subsidiary issues and worst case if the SEE is sitting out in field somewhere, it can be driven under its own power to someplace easier to work from.

I have even considered formalizing the boat tank setup so I can run ag fuel off road without getting the dye in the fuel system. Just have the tank higher than the low pressure fuel pump and tee into the line on the inlet and then have tee in the recirc line to the primary tank with valves to redirect it to the boat tank.

 

[The FLU farm]

Just remembered...it's Belmetric. And don't forget to ask Matt about sending the washers for the banjo fittings, too.

You probably won't need to replace all the fuel lines, but if you can turn one on the fitting, that's a leak point. Also, the gasket on the strainer is a likely source. I replaced mine with an O-ring.

As much trouble as that particular SEE caused initially, after fixing the fuel lines it's been completely dependable. Yesterday I fired it up to install snow chains and it started right up after sitting for about six months.

 

[majkowskid]

ok guys... it deepends.

i have cleaned the tank, including the filter screen at the bottom of the pickup lines (it was gunky). replaced fuel filters, gaskets, and crush washers on filter housing. removed the bypass thing on top of the fuel filter following someone's post on here (the electronic piece on top.. what ever it is) i sued the proper fittings to ensure they are air tight.
replaced sediment screen gasket. replaced the primer pump with the bosch one just to ensure it wasn't faulty.

I can pressurize the tank through the vent port on the top of it... it definitely holds pressure. put around 5 psi in it, and put my finger over it for 30 min. when i remove my finger all the air rushes out.

it takes me no less than 500 pumps of the primer to get fuel to come out of the bleed screws. and yes, that's with everything filled with fuel first... filters, etc.

i can quickly start the mog, and it idles very low like 300 maybe... on verge of dying. i run over to the primer pump and start pumping like a mad man and it will begin to idle properly. as soon as i stop pumping, it chokes and dies. i literally kept pumping for 5-10 min and it will idle.

do yall think the lift pump itself may be bad? exactly how do those little lift pumps operate?

 

[peakbagger]

Sounds like the primary mechanical fuel pump may be bad. Its upstream of the primer pump. First time I have heard of the primary pumps going bad.

 

[majkowskid]

Sounds like the primary mechanical fuel pump may be bad. Its upstream of the primer pump. First time I have heard of the primary pumps going bad.

Can you provide a pic of the pump you’re referring to?

 

[peakbagger]

Good Enough?

 

[majkowskid]

Good Enough?
View attachment 912031

Oh shoot you meant that pump. The 1500$ one lol. I would hope it would not be that. This engine has less than 30 hours on the clock. I would think it would be something nose simple than that

 

[peakbagger]

Not the injection pump, the cam driven plunger pump in the foreground. I think I paid less than 100 bucks for a spare but never installed it during my starting woes.

Of course, the boat tank test doesnt need it.

https://expedition-imports.com/0000902750

 

[majkowskid]

Oh phew! Just ordered one! Will hopefully swap and test next weekend. Someone just told me about a 3rd bleed screw on the side of the actual injection pump. Even posted pics from the manual about it. Gonna try to bleed it there also

 

[The FLU farm]

I don't think you need to worry about bleeding anything. These things are surprisingly self bleeding.

I know many doesn't care for it, but it's easy to sit in the drivers seat and spray some ether into the intake while trying to start them. With a little practice they can also be kept running until the fuel system decides to work. Well, usually.

 

[majkowskid]

I don't think you need to worry about bleeding anything. These things are surprisingly self bleeding.

I know many doesn't care for it, but it's easy to sit in the drivers seat and spray some ether into the intake while trying to start them. With a little practice they can also be kept running until the fuel system decides to work. Well, usually.

Already tried that. No luck. And ether isn’t the best thing for a high compression engine anyways. But I did use it to diagnose that it’s a fuel issue lol. With ether it will start right up and immediately die.

 

[The FLU farm]

Well, they do come with the built-in ether system, so it can't be all bad. If used correctly.

And as mentioned, don't expect the fuel system to catch up and take over after one quick squirt. I still think you have air leaks in the system.

 

[majkowskid]

Well, they do come with the built-in ether system, so it can't be all bad. If used correctly.

And as mentioned, don't expect the fuel system to catch up and take over after one quick squirt. I still think you have air leaks in the system.

That’s what I’m thinking as well. May have a diesel mechanic coming in 2 weeks if the primer pump doesn’t fix it

 

[The FLU farm]

What's a diesel mechanic going to do to the fuel lines that you couldn't?