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Changed fuel filters in MEP-803A... now it won't start.

Ray70

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If you're saying the pin that fits into the slot in the fuel rack does not move freely ( swing left and right about 50 degrees ) then yes your pumps need attention. Before you go replacing them, get a gallon can of the "soaking type " carburator cleaner. Take the pumps out and soak them for a couple days, then pull them out and try working the levers and plungers. I've freed up dozens of them this way.
Many folks will probably disagree with me on this, but you can take all 4 out ( TM says to always leave 1 pump in place to hold rack in position ) and ensure the rack moves freely front to back. However you do need to be careful that the rack doesn't move too far forward and come out of position. I have personally removed all 4 pumps many times and never had a problem with the rack or getting the pumps back into position with the pins engaged in the rack's slots.
If you want to be safe, leave 1 pump in, fix and replace 1, then remove the other pump ( rack should now move freely with 1 good pump installed and shutoff solenoid out of the way )
Be sure to tighten the hold down clamp, otherwise the pump lever with touch the underside of the block giving the impression that the rack is still frozen.
When you remove the pumps, keep track of the plastic shims under the pumps and make sure you put the right shim pack back with each cylinder.
 

jamawieb

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Jamawieb, I did as you said an treated the upper portion of the pumps. The plungers/valves all appear to move with ease but cranking does not send fuel through or spin the plunger.

I read a bunch last night including a thread about fuel in the engine block (one that you all have been involved in) and this has answered a lot of questions. When I purchased mine on Gov Planet I picked up a trailered set that was missing the oil filter. I found water in the engine block, like some of the users here on SS, I've drained the set and changed the oil twice. I have a few questions for you all:

1. I removed an injector pump last night from the engine clock. Are the parts of the pump supposed to move freely? The plunger, spring, valve, washers, etc. all move freely but the black pin and collar do not. I’ve seen a lot of talk here about servicing every last piece of the genset but it seems like people just decide to replace the injector pumps rather than service them. Are the pumps serviceable? Can I soak the entire thing in carb cleaner?

2. I have not seen anyone discuss parts sourcing. Do people recommend Green Mountain Generators? Pumps there are $430 a piece. Are there other places you all would recommend I look?

I’m afraid by fuel rack may be seized with surface oxidation from being exposed to water. When I manipulate the fuel solenoid lever, the rack moves none. Nothing. My next step, I suppose, is to service each pump one by one and then try to get the rack to move. Which, perhaps it will after I clean up the pumps.

The set does crank, meaning, it is not seized like some have had experience with here.
Ok, so the reason it's not starting is because of the pumps. Do not presume you need new pumps, they really do not go to the point of being unserviceable. The pin and collar you reference fit into the fuel rack, the rack is a thin piece of metal that runs along the block, which all the pumps fit into. If the pin is frozen on any of the pumps, then the fuel rack will not move. The fuel rack opens or closes the plunges in the fuel pumps. Do not remove all the fuel pumps at the same time and leave the fuel cutoff solenoid attached because to install or remove the pumps, the fuel rack has to be in the closed position. Leave at least one in place to keep the fuel rack in position.
The first thing I would do is take the pump apart (except for the spring on the bottom) that you removed so you can get an understand of how it works. You will take the top of the pump apart using a 3/4 (some are 11/16) like I explained earlier. Take everything out (spring, delivery valve, etc.) Then you will look down into the pump and you will see the top of the plunger. The plunger moves up and down with pressure applied to the spring on the bottom so try to compress the spring on the bottom and see if you view the plunger moving up and down. I doubt that you will since the pin and collar do not move. Do not take the spring off the bottom. Then soak it in carburetor cleaner and keep compressing the spring and trying to move the pin left or right. When it finally frees, look into the pump again and on top of the plunger you will see a square notch in it, when the pin is moveable you will see the square notch move in relation to the pin. This is how it lets fuel into the pump. The pin should move easily so keep working and using carburetor cleaner until its smooth. In a very seized pump, you will need to take a brass punch and lightly hit the plunger after spraying with carburetor cleaner to break it free.
Then when you get it freed, I leave it apart so I can see the top of the plunger when reinstalling because it can be very difficult to get the pin back into the fuel rack. When you get the pump back into place and you think it's in the rack, you should be able to move the shut off solenoid and see the square notch in the plunger move left to right. You'll have to get the fuel rack moving freely to test and sometimes you'll have to move the adjustment stop bolt out on the block so the fuel rack will move closer to the radiator.
If it were me, I would get an understanding of how the pump works and what I'm visually referencing before moving forward. After you understand what to look for, take the pumps apart while they are in the engine and soak them in carb cleaner, rotate the motor over with the dead crank, until you see the plunger move up and down, finally start moving the fuel cutoff solenoid so the fuel rack will move. After everything is moving free, put it back together and fire it up.
 

HyaliteHeavy

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Thanks for the help guys. I have a new hope now that I've got the pumps blown-up. #1 had a seized plunger - this has now been freed and is soaking for the evening. This kind of help may be in the TMs but I have yet to find anything this helpful. So, thanks for the help so far and I'll be in touch when I get it put back together. If we were all in Montana, I'd take you guys out for a beer.
 

HyaliteHeavy

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So... I accidentally did what you said not to do and released the lower spring and spotted washer from the pump assembly when I was turning the pin & collar to break the corrosion free. Soaked it, everything works great but now, as I imagine you already know I can not get the plunger to stay in the pump sleeve. When I assemble the entire pump everything works and movement is easy. But when I replace the lower spring and washer the tension pulls the plunger from the pump sleeve.

Did I destroy the plunger? Was there a keeper bearing within the sleeve that flew across my shop when the spring and wager dislodged in dramatic fashion? In other news, the other three pumps are now working wonderfully.

Thanks in advance.
 

HyaliteHeavy

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Steel Soldiers,

Today I got my genset running and it’s producing power. Despite what what some have said - everything is NOT in the TMs. The advice and support I received on the forum here was invaluable to getting my generator running. Thanks for everyone who helped.

Getting the injector pumps set back in the fuel rack/governor rack/idle rack was one of the most frustrating and confusing things I’ve ever done. It seems like I struggled more than most and perhaps that’s because all four had popped out during my install. Perhaps I have a bent rack, perhaps I’m not on the same wrenching level as many of you here at SS are. Regardless, patience paid off.

I know a bunch more from reading and troubleshooting but mostly because guys took time out of their day to help out.

Thank you.
 

jamawieb

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It's very difficult the first time, I've walked several people through the process and always say that you must have patience because it's going to take a little while to figure out. After find the sweet spot of everything, it goes a lot faster. It took me several hours for the first time but after I figured out the trick, it takes about an hour now.
 

Guyfang

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Steel Soldiers,

Today I got my genset running and it’s producing power. Despite what what some have said - everything is NOT in the TMs. The advice and support I received on the forum here was invaluable to getting my generator running. Thanks for everyone who helped.

Getting the injector pumps set back in the fuel rack/governor rack/idle rack was one of the most frustrating and confusing things I’ve ever done. It seems like I struggled more than most and perhaps that’s because all four had popped out during my install. Perhaps I have a bent rack, perhaps I’m not on the same wrenching level as many of you here at SS are. Regardless, patience paid off.

I know a bunch more from reading and troubleshooting but mostly because guys took time out of their day to help out.

Thank you.

No book will have it all. But the reason we, (and yes, I am a real nag about this) harp on the books is this.

1. You have to know how it works.
2. You have to know how to operate it right.
3. You have to know why it works.
4. You have to know in what order it works.
5. You have to know what isn't working.

The books help you do all know all this and more. And when you can do all the above, troubleshooting is 1000% easyer to do.

And you supplied the last ingredients. Desire and patience. You done good.
 

HyaliteHeavy

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To GuyFang, DieselAddict, Ray70, jamawieb,

Thank you all for helping me getting my genset running. There have been some complications here are there but for the most part she's running quietly and consistently at my job site and providing us with plenty of power to run all of the equipment that we've needed over the past six weeks. I really appreciate it. I've learned a bunch and I'm pretty intimate with my 803 after having spent so much time covered in diesel and oil. I do have one question:

My injector pumps will occasionally pop out of the fuel rack/idler rack. When they do, the genset belches black smoke and barely runs because (usually) only cylinder 4 is getting fuel. I then have to take all of the high pressure fuel lines off, reset the pumps, etc. etc. I've read a bunch of posts by others where you all are helping to troubleshoot similar problems. So, I've heeded this advice and I have: pulled up on the fuel rack (in case it was bent downwards), I've adjusted the set screws which control the stops for the "fuel cam", and I've messed around a bit with the internal set screw for the fuel rack/idler rack stops. Anyway, the pumps have slipped out a four times now and I'm curious if you all have any additional input so I can avoid it in the future.

Should I screw in or screw out some of the set screws for the "fuel cam" (I take this term to mean the rocker onto which the fuel solenoid attaches and which, in turn, articulates the fuel rack/idler rack?

Should I screw in or screw out the internal set screw for the fuel rack/idler rack stops?

Thanks again, in advance.
 

Ray70

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Hello, So are pumps 1,2 and 3 coming out of the rack and 4 stays in? Also, when this happens do you notice it right at startup, such that it had popped out when the machine shut off last? Or has it ever popped out while the machine was running?
Sounds like either the rack is still bent ( if only 1 or 2 of the center pumps is coming out ) or maybe the rack is moving too far back when it shuts off ( screw the shutoff cam hits when solenoid pushes out is too far backed out ) If I remember, you had difficulty getting the pumps back into place. That is often an indication that the "Set screw" you mentioned is out of adjustment allowing the rack to either move too far or not quite far enough.
There might be an adjustment procedure called out in the TM. Does that screw look like its been messed with? Should be a jam nut on it and possibly a dab of red paint.
 

HyaliteHeavy

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I believe it's happening during the shutoff. It is not happening during operation/while it's running. The first and second time, all of the pumps popped out. The third and forth time, it was 1,2, and 3. Yes, I did have difficulty reinstalling the pumps but now that I have the hang of it, it's fairly easy. As others have noted it's a lot easier when one of the pumps stays put. The shutoff screw for the fuel cam stop has not been moved. There is wire connecting both full throttle and shutoff. There is a jam nut as well as red paint and the paint is aligned.

If I'm taking your meaning, should I barrel-out that screw so the fuel cam cannot retract too far forward (radiator side)?

I did find a set up procedure for those two screws here:
"The key is to feel at that instant where the fuel stops are then adjust the screw out until it just touches the top of the cam, then screw out an additional 2 flats of the screw. This will prevent any further stuck racks. Adjust the lower screw so that there is 26mm distance from the top screw to the top of the fuel cam where it interfaces with the flats. Screw out the lower screw until the proper interface is achieved."

I could follow this procedure if I could determine "where the fuel stops are" but I can not feel this instant.
 

Guyfang

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Sounds to me like the rack is bent. When you had it out, did you lay it on a flat surface? If the set screw looks like it hasn't been fooled with, I tend to let it be. All too many "problems" in gen sets are fooling with things and then not resetting them correctly. Or at all. We called it, "fixing it, till its broke" syndrome.
 

HyaliteHeavy

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I've never had the rack out of the engine case, I've only removed the injector pumps. However, I know that when I pull up or push down on the rack there is a bit of play - say, 3/16". Put another way, the rack will rock up and down a bit when I get my fingers in the inside edge and lightly pull up/push down. I'm not sure if it's normal to have that much play in rack. When at rest I would assume the rack, therefore, sags down a bit. However, the unit has been running just fine for three days now with no interruption.

Copy that, Guyfang, I will not move the fuel stop set screws.
 

Ray70

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If you have trouble again, while the pumps are out, see if the far end of the rack moves up and down. I believe there is a plastic cap molded onto the end of the rack that rides in a passage in the back of the block. I would be curious to see if that plastic has deteriorated and fallen off, causing excessive movement of the rack?? Just another thing to check, if you have problems in the future, but hopefully you do not!
 

The Captain

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I'm more of an experiential type mechanic.

If I open a tap and no water comes out, I don't travel to the reservoir to see if there's water before backtracking from the faucet to the shutoffs underneath, to the mains to see if my basement's flooded, then out in the yard to see if water's bubbling up or the water company has mistakenly turned off my service.

But if you want to discuss SUPPLY-side mechanical engineering, I could get behind that. It works well enough with economics. With this analogy you'd really have to start with the tank, pickup tube, etc.that's an easy enough thing to check by opening a return line at the injector and hitting prime, no?

I thought I had a full tank because I couldn't pour more into it until I removed the extension tube with the screen and saw it was gummed up and fuel would barely dribble through. There WAS fuel, but only about 1-1/2 gallon.

FWIW.
My 813 has the same issue with the gummed up tube fill tube screen. Were you able to clear it out using gumout or something?
 
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