Komatsu PC130

[WoodChuckDad]

I called the dealer this morning and asked to have a mechanic call me. They had one call me who said it sounded like fuel restriction...He said that when an injector goes bad, it doesn't have moments of good performance.....as he described it, the downtime allowed some fuel to get past the blockage and use, burned up the available supply. He even said that I might want to cut up the filter and squeeze it in a vise to see if black crud came out. He suspected I had dirty fuel. I decided to drain the tank..it was full. So I needed somewhere to put it... I found a place to get some 55 gallon steel drums about 40 minutes away and went and picked up 2. I started draining the tank and it was an absolute trickle. So I shoved a small piece of metal wire up the hole and a bunch of metal crap fell out....but it started flowing well. I looked into the tank with a flashlight and there was brownish stain on the walls of the tank...At first i thought it as algae...I took a planting stake and rubbed it agains the wall of the tank....just a brown rust stain. Ok...so there's a little rust crud in the bottom of the tank. I decided to stir it up a bit. I spun the excavator in a circle for a few rotations to get the diesel spinning and try to centralize the debris in the drain bowl.....sort of a redneck centrifuge. I drained it and had to poke the crud out of the way....I did this 4 more times and thought that maybe I didn't need to drain all the fuel...I figured it would be enough and was going to take on the trees.
Didn't even finish filling the hole I made for the barrel to sit under the excavator. It bogged down really bad. So.... I must drain the whole thing.
It was full of crud...I decided to take a stick and carve it to a chisel point and push the stuff to the drain bowl....It didn't drain...it clogged.. I tried several times....no dice.
Now, I had a stroke of genius. I need to vacuum this crap out. Off to purchase a 12V vacuum.....can't find one...buy an inverter that will hook up to truck battery, and a 6 gallon rigid wet vac that is exactly matched to the inverter....what could go wrong?

I head off to buy someone fuel line and something....maybe my spider sense is tingling....and I start to direct my plan. The tank will be empty, except for fumes. Diesel is stable and safe compared to gas. But I'm gonna have a tank of vapor....I know..I'll stop back at the hardware store and buy an extra 15 feet of vacuum hose...that way I won't have the wet vac next to me....I'll put it on the other side of the excavator, and if, by some crazy chance the vapors reach the brushes on the electric motor and find a spark, I will be sheltered from the explosion.......Good plan!
AS I drive back to the property, I start to think a bit more. What happens when a flammable gas burns in a presence of enough oxygen? Rapid explosion and bring....and I'll be holding a hose filled with this mixture....and it could follow that hose back to a 65 gallon air fuel bomb that I'm laying on top of. I'm not sure exactly how powerful that could be, but I think It would move the excavator and obliterate me. Time for another plan. What I need is a pneumatic vacuum. Use an air compressor to create a vacuum without the possibility of a spark. Except it requires an enormous tank and electricity to drive it...and I am trying to do this on the side of a mountain where I have none of these things, 100 miles from home.
Another plan? Since almost everything I have seen in the tank is rust, maybe a magnet would work. I could get a 3 inch flat picked of trim board to push the bulk of the trash to the center, in the drain bowl, then drop a magnet grabber down and pick most of the stuff up. And the stuff that isn't metal rust bits should be small enough to go down the drain hole if I put a couple gallons of diesel back in the tank and swish it around with the stick.
If anyone has a better idea please sound off. I'm still replacing the fuel line.....and if I can find one tomorrow morning, I will put in an inline filter.

 

[EddieWalker]

Just to be clear, the engine starts up fine, then after a short period of time, the engine loses power. Not they hydraulics? I've had both happen, and if it's the engine, then it has to be the fuel not getting to it. Idles fine, but it wont rev up and there is no power to it.

The dirty tank sounds normal. It's gonna be like that in every old piece of equipment. Blowing out the fuel line with an air hose made a HUGE difference when I was going through this. Adding the extra filter also made a big improvement. Finding that screen in the fuel pump was surprise. You didn't mention if you did that or not. But in my New Holland, Case, and Ditchwitch, they all have a sediment screen in their fuel filters that plug up.

I don't know if you will have any luck with the vacuum cleaning idea. It might be time to take off the tank and get it cleaned out thoroughly. While it won't be fun, it is part of owning equipment and what it takes to keep it running. Trust me, if this is the biggest repair you have, you'll be very lucky.

 

[WoodChuckDad]

I can't find a pneumatic vacuum locally so I'm going to manually clean it out. First with a magnet. I know that rust becomes non magnetic but a lot of it is still ferrous enough to draw to a magnet. Hoping some of the crud will come along for the ride. The. I'm gonna use a long flat piece of plastic or if I can find a brewing supply, a mash paddle, to posh it into a pile and grub it out some how. Maybe I'll be able to get it to go thru the spout after the magnetic stuff is out. I'll pump a little more diesel back in to slosh it around.
And yes, it starts fine and idles. But as soon as you do anything it dies out. Could it be the hydraulics? Sure I guess so but I need to eliminate fuel first. I was also told by a mechanic that I can probably remove the valve on the tank to make the hole bigger. That's my las move since I don't want to break the valve.

 

[EddieWalker]

If nothing else, it's still good to clean out the tank. My guess is that something is blocking the flow of fuel, and it's going to take following the entire path from tank to injector to find it.

 

[farmer2009]

Kind of surprising that there isn't a clean out plug. About 1 1/2 or 2 inches. The dozer has one beside the shut off valve.

 

[WoodChuckDad]

There is just a drain valve and the fuel line on the bottom that I can find. I used the magnet and a plastic scraper duct taped to a stick. I ended up with this crud from the magnet.



Also got some more stuff to flush. There is still some rust in there but it is a night and day difference. I'm going to instal the new fuel line in the morning. I also bought an inline filter from TSC. Dutton-Lainson Goldenrod 496 Water-Block Absorbing Fuel Filter - For Life Out Here.

I'm not sure how to mount it or where to get the fittings to reduce it to 3/8 inch. I'm wondering if I can get that at lowes. I'm exhausted. And I still don't have it running yet.

 

[gghb]

when you get the tank and fuel lines clean before you crank engine i would blow out the line back to tank that will hopefully clean the crap out of the shut off valve then clean the screen that should be on the inlet side of the injector pump

Greg. p.

 

[WoodChuckDad]

when you get the tank and fuel lines clean before you crank engine i would blow out the line back to tank that will hopefully clean the crap out of the shut off valve then clean the screen that should be on the inlet side of the injector pump

Greg. p.

I am replacing the line from the tank. I imagine the old one is full of crud.

 

[DT86]

The shop vac plan works. Diesel or diesel vapor will not go boom, from a spark or even open flame.

Skip to 3:20 in this video for diesel.

Jet Fuel VS Diesel VS Gasoline how they burn and what color are they. - YouTube

 

[WoodChuckDad]

I am replacing the line from the tank. I imagine the old one is full of crud.

From what I understood in the video, diesel WILL burn when atomized. That is what happens when you pull the vapor thru a shop vac.. If it was just liquid, it would probably be ok, but the vapor in an empty tank is flammable, and pulling it thru the vacuum and increasing the amount of air and oxygen in it is creating a combustable situation.

 

[MinnesotaEric]

I have the grease solution. Put on a 12" hose for an excavator and you're set for field greasing.

 

[WoodChuckDad]

I have the grease solution. Put on a 12" hose for an excavator and you're set for field greasing.

I was thinking that same thing.

 

[kevin37b]

Make sure the hose from aircleaner to turbo is not collapsing under load .Have seen it happen .

 

[WoodChuckDad]

Make sure the hose from aircleaner to turbo is not collapsing under load .Have seen it happen .

I don't think that is happening. It appears to be fine. And the symptoms don't match a collapsing air line, because it is fine for the first couple minutes, then it dies out.

 

[WoodChuckDad]

Here is the readers digest of what I have done so far.
Change spin on fuel filter
drain fuel from tank
remove crud from tank
flush tank several times with diesel to get out crud residue
replace fuel line from tank
install inline fuel filter. A smaller one that is see thru
replace spin on fuel filter

The symptoms remain the same. After priming the lines, I can start it up, run for a few minutes and then it dies. I can prime it again, and it will immediately start running well for about 3 minutes. the last time I did this, since it was already warm, I just started digging at a stump. IT was fine for 2 minutes, 30 seconds. Then it crapped out.

Any ideas?

 

[farmer2009]

How much tank return are you getting?

I have a retired cat mechanic that's my go to when I get stumped. He says the injector pump should return 2/3 of the fuel it receives.

After priming if you remove the supply line at the injector pump. How long will it continue to run full? If about 2 minutes then you have a supply problem. Catch the fuel no sense in wasting it.

Is there a lift pump in the system? Is the primping pump also used during operation?

Did you make sure the tank shut off valve wasn't clogged?

Still a possibility the injector pump is headed out. Worst case I know.

 

[EddieWalker]

How does the fuel line go into the tank? Is there a metal tube in the tank with a screen on it?

You didn't mention taking apart the fuel pump. I guest it's possible, but I find it very hard to believe that there isn't a screen of some sort in the fuel pump.

What else does the fuel line connect to? At every fitting, you have the potential of some sort of blockage.

 

[WoodChuckDad]

How much tank return are you getting? I have a retired cat mechanic that's my go to when I get stumped. He says the injector pump should return 2/3 of the fuel it receives. After priming if you remove the supply line at the injector pump. How long will it continue to run full? If about 2 minutes then you have a supply problem. Catch the fuel no sense in wasting it. Is there a lift pump in the system? Is the primping pump also used during operation? Did you make sure the tank shut off valve wasn't clogged? Still a possibility the injector pump is headed out. Worst case I know.

How would I tell how much return I get?

 

[gghb]

the worst fuel problem i've ever had was caused by a factory tag wearing through a steel line on the suck side of the fuel pump sucked air but didn't leak fuel found it by pressureizing fuel tank and finding diesel spot on suck side

Greg

 

[WoodChuckDad]

How does the fuel line go into the tank? Is there a metal tube in the tank with a screen on it? You didn't mention taking apart the fuel pump. I guest it's possible, but I find it very hard to believe that there isn't a screen of some sort in the fuel pump. What else does the fuel line connect to? At every fitting, you have the potential of some sort of blockage.

Fuel line hoes into bottom of tank in the bowl Metal tube that sticks up a couple inches and out the bottom making an elbow for a couple inches. I noted that out and removed some crap from it but it is clear now. The line runs to the inline that I put in then to the injector ( I think it is the injector) I did not attempt to take the injector apart. I don't have a shop manual and wouldn't know where to begin.