Deutz 4 cyl. diesel start, stall, run slow, stop, repeat

[PowerTracManiac]

Wait a little bit and it will start right up again and run for a short time then run very slow then die out?
I'm thinking fuel flow blockage.

The fuel exit line is up high on my tank. Must be a tube that goes down to the bottom of tank and the fuel pump or injectors I guess must create suction to get fuel up to the engine?
I don't see a fuel filter and I don't have fuel pressure guage on the machine.

My plan is to disconnect the main fuel line at the fuel motor line (there is a hose clamp there) place a rag over the gas intake cap and blow compressed air into the tank and see if the fuel comes up and out of main tank line?
Any thoughts on that?
Also, if I pinch off the line to the injectors on the fuel line portion that goes to the engine before I disconnect the main line from tank will that be OK or will I have some sort of a priming issue with the Duetz?

 

[agjones]

When mine did the same thing it was water in the diesel. Changed the filter, added a separator in line good to go.

I think you're right about the clamp and prime. But someone else will know better than me.

 

[ponytug]

I believe that the diesel line in the photograph is the diesel return line. The main outlet is usually in the center of the bottom floor of the tank.

The symptoms sound like fuel starvation. The number one cause is bad fuel, though it would not hurt to check for water in the fuel. You can shine a bright light into the fuel tank to see if the bottom is clean. You can also see how clean the screen in the tank is. My 3 cylinder Deutz has a clear fuel prefilter in the fuel line, a prefilter on the engine just before the fuel pump, and a screw on filter on the pump itself. As a heads up, some of the other owners have found quite a bit of crud on the engine pump prefilter, so be sure you take it out and check it.

I do not know if it helps, but here is a quick overview of the fuel system. The fuel flows by gravity and vacuum through the prefilters and filter to the fuel pump that boosts the diesel to an intermediate pressure before going to the injectors, where the diesel is split, with the bulk of it being used hydraulically to boost a little bit of diesel to injection pressure into the cylinder. The bulk of the diesel is returned to the tank. This means that Deutz engines rarely need priming, and has the added effect of extensively filtering the diesel through multiple passes through the fuel filter.

Good luck! I hope that it just is a bad batch of fuel that clogged your filter.

All the best,

Peter

 

[PowerTracManiac]

Very helpful!
Seems that I am on the right track with a fuel related issue. I was wondering about that fuel line in my photo and it seemed odd to me the way it was run. Haha! Makes more sense that it is a return line as you said.
Will check the bottom of my fuel tank for more lines and with a flashlight this weekend.

 

[m5040]

You said you didn't see a fuel filter. You do have one and with the tolerances on a diesel injection pump they are vital. You should start by locating and then changing the fuel filter. When you have it off, pour it into a clear container and if it has water, there will be noticeable bubbles on the bottom. If a lot of water, drain the tank enough to get it out or it will grow algae. A good diesel fuel supplement that deals with water would be a good idea for you (if you find water in filter).

 

[woodlandfarms]

On my deutz and probably yours the fuel comes out of the bottom of the tank and is gravity fed over to the pump. On the front of the pump is a philips screw. Undo this and pry it forward. There is a circular filter. Clean and replace. It is the filter that used to plug up on me. Then the fuel goes to the fuel filter and then up yo the injectors. The injectors are mechanical, meaning the cam in the engine pushes on them and causes them to spray fuel into the engine at high pressure. The unused fuel then flows back to the tank. I have fought minor fuel issues like water in the tank and sediment in the tank. I ended up cutting a hatch for my tank and coating it in POR paint. I also bought a water removing filter for my fuel pump. In addition i made a 50 gallon fuel carrier that i can pickle fork into the truck to get off road diesel.

 

[PowerTracManiac]

You are correct and my fuel supply does gravity feed from the bottom of the fuel tank. The other fuel lines in the previous photo are return lines as stated.
My supply fuel line comes from bottom of tank to a gold canister mounted on a silver block. There are 2 wires coming off the silver block and it says flow on it with an arrow.
Fuel line then goes to the fuel pump and the fuel filter before going to engine.

The machine started running rough/slower and I parked it after running it for about 45 minutes.
I let it cool down and then I added fuel.
The fuel that I added to the machine had been sitting for about 4 month outside in a plastic 5 gallon deisel container.
I don't have a fuel/water seperator and I will purchase to add to my fuel fill process.

Anybody know what that gold canister/silver block is?

If I disconnect the fuel lines or remove the fuel pump cover to clean out the fuel pump canister do I have to do some sort of priming process before I try to start it again?

 

[woodlandfarms]

Duetz 4 cyl. deisel start, stall, run slow, stop, repeat

I am not sure but the first photo looks like a electric in off valve. Mine does not have this. The second picture is you PRE filter and lift pump. Undo the Philips to find the filter screen. And it is the single philips on the round cap.

 

[woodlandfarms]

Oh. No priming. Just takes a moment when turning over. I installed a manual on off valve on my fuel line to keep the fuel in the tank when changing filters.

 

[m5040]

In your picture (top) the gold object looks to me to be a fuel filter (that may be restricted), the silver item looks like a inexpensive electric pulse fuel pump. You shouldn't need these as the other picture shows the factory mechanical lift pump (very high quality). I would get rid of that electic pump and fix the factory pump (if it is broken). Like woodlandfarms said, there should be a screen to keep particles out of the factory pump. The previous owner might not have known this and installed the electric pump to try to push through the clog. Now it may be so bad, it will have to be cleaned.
ALSO it looks like at least one of your fuel line hoses is weather cracked. The lines on the Deutz tend to move around quite a bit. You should change bad lines before it breaks and you get a fuel leak on a hot engine.

 

[ponytug]

First, I would clean the prescreen as Woodlandfarms suggested, and then change the fuel filter. If that does not fix your problem, I would do the following;

+1 on changing that cracked fuel line. A little air could go a long way to explaining your engine symptoms. You might want to change everything while you are in there.

In general, on a diesel engine the strategy is to filter first, then pump as this traps the most debris and water. (The water does not get emulsified by the pump.) I can not think of a reason why there would be a pump inserted there for a Deutz engine.

That said, I have no idea if it is a pump or a shut off valve. If it is a pump, I would remove it. If it is a shut off valve, it may have been installed instead of replacing a failed Deutz solenoid that tend to be pricey. If it is a fuel solenoid, you do need an electric fuel shut off somewhere to stop the engine, or you will have to open the hood and manually flip the fuel shut off lever every time that you want to stop the engine. You might want to find that lever before removing the silver gizmo from the fuel line...(back left corner of the engine block.) If it is a flakey solenoid valve, it might also explain your fuel starvation issues. Have you checked the wiring on it to verify that it gets, and keeps, 12V when the engine is running?

Unless you are seeing crud or water in your diesel, probably do not need to prefilter your diesel. If, like Woodlandfarms, you live somewhere damp and rainy, it may also be worth it to upgrade your engine fuel filter to a water blocking filter. Again, the Deutz filtration is both very good and quite tolerant of impurities, assuming that the prefilter gets cleaned regularly and the fuel filter gets changed as needed.

Good luck!

All the best,

Peter

 

[woodlandfarms]

I just looked at your picture again, it must be a newer Deutz. Your hoses run slightly different than mine but it is all the same in the end. Also just noticed your dipstick is broke. So is mine. Have yet to get around to ordering anew one.

 

[woodlandfarms]

So ptm, Any update?

 

[PowerTracManiac]

You guys are awesome!
The update is that the round prefilter at the motor was totally clogged with fine debris.




Some small disappointments did become evident with this partial repair.
To clean the prefilter I had to buy a fuel line clamp because there is no petcock on my gas tank. ( -1 for P.T. )
The PO placed another filter previous to the prefilter and it must not be very good quality for this much debris to be in the prefilter.


I think the debris in the prefilter mesh is very fine rust particles from my tank? My tank is one large welded assembly and I don't think it is coated on the inside as far as I can tell? (Is that another -1 for P.T.?)

I need to use the machine now so I am going ahead "as is" cause she runs perfectly again.
In the future, the upgrades that WF, others suggested might be necessary (clean and line the inside of fuel tank, add petcock, etc.).
I will definitely change the weather cracked/old fuel lines as sugessted.

 

[m5040]

Why don't you wait and see how long it takes for that screen to plug again. You were probably the first person to look at it since the factory put it together and it most likely caught all the assembly debris that is now out of the system or settle in and compact. You should always keep a steel fuel tank at full because any part above the fuel level will collect moisture and rust. This is common with all equipment and where you can get water in your fuel. That is reason for plastic type tanks.

 

[ponytug]

Congratulations on finding the problem! Nice photos: that is a slick looking fuel line clamp. I cheat and use a vice grips, with padding on the jaws.

PT put in a prefilter to the prefilter on my machine, but it is pretty coarse and really only catches huge stuff, like fuel line shavings.

In my limited experience, there seem to be more than a few Deutz owners who do not know about the prefilter. So, +1 on it being possible that you are the first person to clean it, and that represents years of gunk accumulating. If the inside of tank looks clean, I think that you should be in good shape with a cleaned prefilter and a new fuel filter.

All the best,

Peter

 

[woodlandfarms]

I’ll get you pictures if you want but I had water in my tank and it effected both filters constantly. I ended up cutting a hatch on my tank so I could scrub it out then I put in some POR paint. That was a huge save for me. So what was the gold and silver device with the wires?

 

[woodlandfarms]

Hey ptm. Just looked at your pictures. Did you buy a new PRE filter for this one or re use it? I ask because it seems a bit rough and the bottom looks like it would have a hard time sealing. And to that did you replace your main fuel filter? If so did you cut open the first? When I was having my rust issue I cut open my filter. It was shocking to see how much debris was in it. But I also cut open all my filters on all of my machines.

 

[PowerTracManiac]

I need to run machine while the weather is good and I am super busy right now.
Have not changed the filters. Reused the old prescreen at the engine after cleaning.

When I get more time, I will replace and cut the filters to check.

Gold canister is a fuel filter and the silver block is a fuel pump.
Didn't get to testing that as the prefilter cleaning worked to get the machine going again. If the fuel pump is not working, it allows enough fuel to pass through it so that the machine runs perfectly.

Future testing will involve figuring out if the silver fuel pump from the PO is doing anything, filters, lines etc.?
Will update as I have time to work on the repairs.

Plan now is to see how long she runs with the cleaned prescreen.

 

[PowerTracManiac]

Well it was about 4 minutes that it ran perfect. Then same thing. Motor slows way down, then dies out. Let it sit for a minute, starts right up and then repeats.
Going to have to go through the entire fuel system.
Don't have enough time to work on it right now as I'm to busy with my regular job.

Wish there was a P.T. mobile guy to call for repairs.