Fuel in Crankcase

[JAJ]

Yeah that’s what I was thinking but couldn’t understand how it would work. I thought there would have been a larger seal around the roller piece as well but after reading your message I have looked over the pics again and now see how this would work. The culprit seal would be indeed the small one around the push rod!

Still needs the new seal kit I wouldn’t trust it, especially not for too long as it is already worn out, but well done though.

 

[Jbaker1]

What I gather is he made/found a “fatter” push rod & the old seal is sealing around it..

Pump Guy that’s exactly what I did. Only a temporary fix to get me out of a jam. I’m still needing the number where I can order that seal.
It’s still holding the diesel out of the oil but I don’t know how long. The gasket kit along with primer pump is supposed to be here Monday.
JAJ I changed the fuel filter. Where could it be getting air?

 

[JAJ]

Ah very good!

What exactly is it doing? Missing, blowing smoke, not getting to full revs, getting full revs but lacking power under load….?? That info might point where to look.

It could have an air leak anywhere on the suction side up to and including the supply pump. Have you checked the fuel lines for flow and partial blockages?
If you have rubber lines it could have an air leak under suction or vacuum but not leak fuel out.

Does it have a fuel strainer (course filter) as well as a main filter?

Just some thoughts, but a description of symptoms could point in different directions.

 

[thepumpguysc]

Sorry about not getting u the p# of the seal.. I’m busier than a 1 legged man in an a$$ kickin contest.!! I’ll get it..

 

[Jbaker1]

Under load it produces black smoke and bogs down as if the governor isn’t working properly. If I’m understanding this correctly, in order for the governor to work correctly the fuel supply has to be correct as well. Today it’s rained off and on. I did get a chance to take the inline shut off valve off thinking it was to small ID that it wasn’t getting the proper amount of fuel. Do you fellas know what the inlet fuel line proper ID is for a 4 cylinder? Suction side, on all points seems to be tight. One reason I think it is still a fuel issue is: when I first start it you can’t hardly get off the switch key fast enough for it not to start. After using it for a little while, and I can’t get my leg up high enough, fast enough and it stalls, it is hard to start.

 

[Jbaker1]

Sorry about not getting u the p# of the seal.. I’m busier than a 1 legged man in an a$$ kickin contest.!! I’ll get it..

No problem. This guy wants me to build him a road, but he’s been waiting awhile and he is intent on me doing it. Just when you get time. In the meantime I’m just keeping a close watch on the “repaired” one’s performance.

 

[Jbaker1]

JAJ, I think the only filter it has is the screw on filter and it does have a strainer in the sp.

 

[thepumpguysc]

I was just getting ready to ask u about the strainer in the inlet banjo bolt below the hand primer..
If u could get a helper to work the hand primer when it starts to bog or when it starts blowing smoke.. THAT might tell u if it’s a fuel supply issue..??
How did the piston in the supply pump look.?? Any deep scratches.?? 90% of them need to be replaced due to scratch’s/ gouges.. u should check the housing where the piston rides for the same..
Does this pump carry an overflow valve.?? Have u checked it.??

 

[thepumpguysc]

I just went back and found a pic of the side of the pump..
No overflow valve..at least u don’t have to fight THAT..

 

[Jbaker1]

I was just getting ready to ask u about the strainer in the inlet banjo bolt below the hand primer..
If u could get a helper to work the hand primer when it starts to bog or when it starts blowing smoke.. THAT might tell u if it’s a fuel supply issue..??
How did the piston in the supply pump look.?? Any deep scratches.?? 90% of them need to be replaced due to scratch’s/ gouges.. u should check the housing where the piston rides for the same..
Does this pump carry an overflow valve.?? Have u checked it.??

Piston? I’ve had some refer to the plastic, what some diagrams refer to as plungers, as pistons. Are you talking about what the push rod seats in and the spring sets in the groove on the other side. The other end of the spring rest against the large nut on outside of sp.

 

[Jbaker1]

I just went back and found a pic of the side of the pump..
No overflow valve..at least u don’t have to fight THAT..

That’s correct. Do you think the shut off valve may have been not letting it get enough fuel? It reduced the line from 1/4 ID to 1/8 ID.

 

[Jbaker1]

Oh my! It’s midnight where I live! We probably should talk about this later.

 

[Jbaker1]

I’m checking to see if all moving parts of pump are in the repair kit. I will let you know. Good night.

 

[thepumpguysc]

There’s only 1 piston/plunger..
Yes, what the big spring sits in.

I know whatcha mean, it’s late, it’s almost 2:00am here..

 

[JAJ]

Black smoke and lacking power sounds like too much fuel (or fuel at the wrong time) and not enough air to burn it! Did this start suddenly or has it been a problem since you got the dozer?
How long have you had the dozer?

Have you checked for a blocked air intake or air filter?

 

[Jbaker1]

Black smoke and lacking power sounds like too much fuel (or fuel at the wrong time) and not enough air to burn it! Did this start suddenly or has it been a problem since you got the dozer?
How long have you had the dozer?

Have you checked for a blocked air intake or air filter?

I’ve had the dozer for a few years. It was such a honey of an operations dozer. Initially a friend dropped it off at the church camp I was building out of a hay meadow. After awhile he offered me a deal I couldn’t refuse and I bought it. At that time, wrong decision, about all I knew was how to drive it. I knew to check all fluids before I got in the seat, but that’s about it.
Then I got a crash course in blown hydraulic lines and leaking cylinders. Little by little I began to grasp the importance of clean fuel and air filters. When I retired in 2019, because of failing health the dozer sat idle for probably a year, maybe longer.
When I started using it again, it just didn’t seem like its efficiency was as good as it should be. The black smoke loss of power began to show up and my son, who was an OTR truck driver (he owned his own truck) told me to pay closer attention to air filters, fuel filters and quality fuels. A little while back (I’m not using it everyday) I began to notice this fuel in oil. However, it wasn’t very much. At first it was puzzling to me, instead of having to add oil it would sometimes read just a little over full.
However, best I can remember, that’s when loss of power began to be recognizable to me.
I pulled the injectors, had them tested (all good).
I just knew getting this sp working properly, changing fuel and air filters, would solve the problem and it may be when I get this sp overhauled properly every thing will settle in. Gasket kit is supposed to be here tomorrow and pump guy is getting me the number for the seal. Hopefully my cobbling will hold up until I get the new seal. I’ll double check the fuel suction side, the air flow, etc.
Is there an adjustment device on the fuel side that will allow me to tweak till I get it fine tuned?
I’ve already removed the fuel shut off valve that had the 1/8 inch ID thinking maybe it was too small. Tomorrow i’m planning on replacing rubber fuel supply line and installing the proper shut off valve.

 

[Jbaker1]

Black smoke and lacking power sounds like too much fuel (or fuel at the wrong time) and not enough air to burn it! Did this start suddenly or has it been a problem since you got the dozer?
How long have you had the dozer?

Have you checked for a blocked air intake or air filter?

Good morning. I just want to say again how much I appreciate the quality help I have received on this dozer fuel problem. I know you fellas can tell I’ve been my own worst enemy because of my lack of knowledge and because of that, many problems could have been prevented if the subtle changes had been dealt with.
In our area there aren’t many diesel mechanics and those that are don’t like the word Mitsubishi. Because of that I’ve tackled some pretty big projects, mostly under carriage.
Meanwhile, JAJ, the loss of power, governor not kicking in and the smoke issue, best I remember, all seemed to be about the time I noticed fuel in oil.
Today, I intend to install the gasket kit. I’m also going to look closely at the piston Pump Guy told me about. As soon as I get the new seal, I’ll replace it and, hopefully I can rebuild the pump compartment completely.

I’m going to take a very close look at the intake system. I think I changed the filter recently but if not, I’ll change that as well. I’m going to double check the complete fuel train, from tank to injectors and make sure everything’s good and tight. I’ll post again if I run into the unknown and when I can field test and the results of that. Y’all have a great day!

 

[JAJ]

Good morning. I just want to say again how much I appreciate the quality help I have received on this dozer fuel problem. I know you fellas can tell I’ve been my own worst enemy because of my lack of knowledge and because of that, many problems could have been prevented if the subtle changes had been dealt with.
In our area there aren’t many diesel mechanics and those that are don’t like the word Mitsubishi. Because of that I’ve tackled some pretty big projects, mostly under carriage.
Meanwhile, JAJ, the loss of power, governor not kicking in and the smoke issue, best I remember, all seemed to be about the time I noticed fuel in oil.
Today, I intend to install the gasket kit. I’m also going to look closely at the piston Pump Guy told me about. As soon as I get the new seal, I’ll replace it and, hopefully I can rebuild the pump compartment completely.

I’m going to take a very close look at the intake system. I think I changed the filter recently but if not, I’ll change that as well. I’m going to double check the complete fuel train, from tank to injectors and make sure everything’s good and tight. I’ll post again if I run into the unknown and when I can field test and the results of that. Y’all have a great day!

Hey sorry I have had a bit going on here and haven’t had a chance to reply. I have been thinking about your drama though…. The fact that it’s a new sudden thing that has happened is interesting! Makes me think it could be something simple.
Pumpguy would know if the governor could need adjusting, but I think if it hasn’t been messed with it shouldn’t need it??? Have you adjusted the pump timing or could it have come loose and moved a bit? You have already ruled out the injectors.

I have a very silly idea to try…. That you probably have already thought of… if it is starving for fuel like you think it is, have you checked the breather or vent on the fuel tank? Might be blocked or partially blocked. Would explain why it starts up fine and starts loosing power after a short time. If the breather looks/seems good you could double check it by running it for a while and then unscrewing the fuel cap listening for it sucking air back into the tank to fill the vacuum.
If it sat for quite a time while you were unwell it would be a candidate for clogged breathers.

Hope you are having some luck with it!!
If you get a chance could you post a pic of your dozer? I would like to see the beast in question if you don’t mind?

 

[Jbaker1]

Good morning, JAJ. I know about that, “a lot going on here” stuff for sure. No worries!
Sounds like Pump Guy is in the same “boat”! He said it had rained at his place for the last 24 hours.
I received the kit yesterday and for starters, only installed the primer pump since mine was short and had missing spring. Oil still looked good, no diesel.
I took it for a test. It was better, but still not like I remembered, sound

 

[Jbaker1]

And performance as well. I kept at it for a bit and it started working just fine intermittently. Backing up was a challenge, and that’s what got my attention. After sluggish performance for a bit, suddenly it moved backwards like a champ, started cutting and spinning the tracks. Then it would go back to misbehaving.

Pump Guy had some interesting ideas about the pumping compartment, maybe a faulty piston.
Today I’m pulling the pump and rebuilding what I can until I get the seal, and maybe a rebuild kit for the pump compartment.

Yesterday, When I finished with the test run, let it sit for a few, checked the oil. Looked like the fuel was back.
So, I don’t know if the pump was working correctly off and on was giving me moments of peak performance or if something else is going on.
Good idea on the vent. Had not thought of it. That’s the first thing I’ll check (per your instructions), after I check the oil and start it.