MEP-803a Crankcase full of fuel...

[rhurey]

Power went out last night. Started the generator fine, went inside and about 20 minutes later the unit shuts down. Low oil pressure.

Check the oil, and it's not oil, the crankcase is full of fuel. So that's bad.

It's gonna be at least a week before I can get the thing into the garage to get the cover off and start figuring this out. Any guesses on what went wrong in the mean time?

Of course, this would happen at the end of a week off work, because now I have no free time.

 

[jamawieb]

You know it's either going to be the injector pumps or injectors. My money would be on a bad injector that is flooding the combustion chamber. Did you notice it running poorly before it shut down?

 

[just me]

Injector pump seal at the drive gear. Hope you didn't kill your bearings.

 

[rhurey]

Ok, so I'm looking through the TM's, and I must be missing one, cause there doesn't seem to be a lot on diagnosing this. And I'm learning as I go, which has moments.

Drained the oil, got about 2.5 gallons out.

 

[jamawieb]

I've never seen it in the TM and have not heard of it happening in the 802 or 803. The only advice I could give is to pull each injector pump one at a time and test it but you'll need a fuel pump to apply pressure to the pump to see if it's leaking. You could, take the outlet hard line off your fuel pump on the generator and make a hose that would fit on that and on the injector pump itself. With the amount of diesel in the crankcase you should see diesel dripping from the bottom of the injector pump at a good rate. Read the TM on the removal of the injector pumps and leave at least one pump in place (Do not remove all the pumps at once).

 

[rhurey]

Spare fuel pump I was about to order for another project, so that's easy enough to get. Now I just need some concrete to cure so I can play Tetris with all my junk to get the 803 moved inside, since it's gonna rain for the next 6 months and I'd rather work on this indoors.

 

[DiverDarrell]

I'm about tired of this rain. Hope you get your gen back up and running, were supposed to have another wet and colder winter.

 

[Guyfang]

You want to pay real close attention to what JAMAWIEB wrote here. If you remove both injector pumps at the same time, it's much harder to get them back into the fuel rack and adjusted right. The only time I ever saw any problem like this was bad rings. So when you get done checking the injector pumps, and they work, do a compression check.

Used to live in Graham, Wa. Loved it. And yes, it can rain. Reminded me of living here in Germany. Never go anywhere without a rain jacket!

 

[rhurey]

Got it indoors. And the cover off.

While there's no puddle of fuel near the injectors, one has a rust pool.


And there's a strong smell of diesel from the pumps.


And so ended my free time for today.

So tomorrow I'll likely start to pull the pumps (one at a time) and see how they look.

 

[jamawieb]

Now if an injector is bad, you won't be able to tell without pulling them out. With that much diesel in the crankcase, if the injector is the culprit, usually the tip of the injector will be extremely clean (like it has been washed). A normal injector tip will be black with carbon on it. Now, my reference does not always happen but I usually use a small camera to peer into the injector port to see the internals. By using the camera I can tell with 99% accuracy if the injector is leaking because it will be perfectly clean on the top of the piston and the bottom of the head. In a normal engine, the top of the piston and top of the head will be black with carbon. Hope this helps.

Make sure you read the TM on the removal of the pumps before you start because you need to have the fuel rail at the right position or the pumps can not be removed. My very first generator I worked on, I spent hours trying to figure out how to get the pump out because I didn't have the rail at the correct position.

 

[Guyfang]

There are many advantages to reading! I once pulled an injector pump off a MEP-115A, without reading how to go about it. Two days later, I got it to run again. Should have taken about 2 hours. Yep reading has certain advantages.

 

[rhurey]

So, while I wait for more free time I've been trying to see if I can think my way through this.

When I got the unit ~5 hours of run time ago, the oil level was correct and looked it looked good. But the fuel system had a lot of water in it. While bleeding the water out, I loosened the injector pump outputs, and perhaps wasn't precise about making sure they didn't rotate when re-tightening the lines. Excuses for why.

There a chance that's the root of my misery here?

 

[jamawieb]

So, while I wait for more free time I've been trying to see if I can think my way through this.

When I got the unit ~5 hours of run time ago, the oil level was correct and looked it looked good. But the fuel system had a lot of water in it. While bleeding the water out, I loosened the injector pump outputs, and perhaps wasn't precise about making sure they didn't rotate when re-tightening the lines. Excuses for why.

There a chance that's the root of my misery here?

Nope, that would not cause your problem. Lets say you let the pumps rotate a little, all that is going to do is increase or decrease the amount of fuel it sends to the injectors (a tad). This is how we adjust the injector pumps to become perfectly in time with one another. What you do is take a temp gauge and shoot it at each exhaust port and the higher the temp the more fuel that cylinder is receiving, so you could turn the pump counter clockwise to decrease the amount of fuel.

 

[Haoleb]

Nope, that would not cause your problem. Lets say you let the pumps rotate a little, all that is going to do is increase or decrease the amount of fuel it sends to the injectors (a tad). This is how we adjust the injector pumps to become perfectly in time with one another. What you do is take a temp gauge and shoot it at each exhaust port and the higher the temp the more fuel that cylinder is receiving, so you could turn the pump counter clockwise to decrease the amount of fuel.

Good tip. I am hoping to get a laser thermometer and plan on doing this to see how my engine is running. It sounds easy enough.

 

[rhurey]

Pulled the injectors.



That's suspicious.

In the picture above it's the one with the rust around it.

 

[jamawieb]

Pulled the injectors.

View attachment 657382View attachment 657383

That's suspicious.

In the picture above it's the one with the rust around it.

It's not the injector causing the problem but if you keep up with which cylinder the injectors came out of, we may be able to find which pump is the problem. Looking at the 2nd picture, where you took it from the tips. The 2nd injector from the left, looks dryer than the others, I don't see any carbon build up. I would expect that on an injector where it's independent injector pump seal is shot and it's not able to build enough pressure to pop the injector. The rest of the injectors look normal except that one.

 

[Korgoth1]

Cylinder probably rusted out, no compression on that cylinder-no combustion, all the fuel bleeds down into crankcase.

 

[jamawieb]

Cylinder probably rusted out, no compression on that cylinder-no combustion, all the fuel bleeds down into crankcase.

That's what I would think too but he said that he has been using the generator and I'm assuming running good. This engine running on 3 cylinders sounds awful and can't take a lot of load. I guess we should have asked how well the generator has been running?

 

[rhurey]

I *thought* it was running good.

It ran with 12.5kw load 2 months ago for ~30 minutes without a stutter. Little tinge of gray in the smoke with that load, but that's it.

I have nothing to compare it to besides diesel trucks for sound, but it didn't sound like a train wreck. Maybe I got a video...
Yup: Last April: https://1drv.ms/v/s!AnhaA1TwRcf6kcBMbzwTPZspYFd1Yg

Odds the rings got blown out by GP (or I) trying to start it with a fuel filter full of water?

Also, any leads on what size compression test kit this thing needs? Everything I see seems targeted to screw in glow plug holes...

 

[jamawieb]

If you were running 12.5kw load, your compression is good. The video sounded good.
I would move on to the pumps and if you remember which pump was connected to that dry injector, I would start with that one because I bet that one is the problem.