MEP-803A Repair Assistance

[Mullaney]

Free electric stove left out for the trash works for me as both a load bank and a powder coating oven!

.
An old stove also works REALLY WELL to keep welding rods warm and dry.
When the coating is dry and clean - makes all the difference in weld quality.
Lowest possible setting in the oven...

 

[Lucky Bud]

Free electric stove left out for the trash works for me as both a load bank and a powder coating oven!

Good idea
having an electrician friend come over to supervise .
will shoot it with the bowling ball cannon when we’re done.

 

[justinn]

Did you ever figure out the issue?

I am having a very similar problem with one of my 803A sets. 2010 - no reset- ~600 hours on set, Fresh fuel/filters, pump consistently returning fuel. Starts and runs fine when cold(usual black smoke on start up), but as it warms up, the rpm starts to oscillate and gets progressively worse until it dies. It will not restart until it cools down again. Load or no load doesn't affect it. I've pulled all of the IP's, inspected and cleaned them, made sure that they were seated correctly in the rack when reinstalling, etc... Decently good on that front

Here's the kicker. When it's cold, the rack has the normal amount of tension on it(I have a few 803A's), and will default to the clockwise position without the shut off solenoid connected. However, when it's warm, it has no tension on the rack whatsoever, and therefore will not spring clockwise in its normal resting state. When it cools off, the tension will return and the gen will restart. When it starts hunting, you can disconnect the cut off solenoid and feel the lack of tension on the rack well before it dies out, although there is still some tension left toward the counter clockwise position(i.e. you can shut it off).

This is definitely not the cleanest set that I own, and there was quite a bit of corrosion when I peered down the IP Ports, but the rack looked corrosion free(the little bit I could see of it). I was ~trying to avoid digging in to the cover on the front, but I can't think of anything else to do without yanking it.

FWIW, Not a single fleck of paint had been knocked off any of the bolts/nuts, injectors, etc.... so it looks as if no-one was ever in to this thing.

I also know about the droop settings, and was thinking to start exploring that as an option before I pull the front cover. Then I ran across this thread and seemed very similar to what I was experiencing, but with no answer. So I posted in here. If you guys want me to start a new thread, I can.

Thoughts? and as always, Thank you.

Justin

 

[Lucky Bud]

Did you ever figure out the issue?

I am having a very similar problem with one of my 803A sets. 2010 - no reset- ~600 hours on set, Fresh fuel/filters, pump consistently returning fuel. Starts and runs fine when cold(usual black smoke on start up), but as it warms up, the rpm starts to oscillate and gets progressively worse until it dies. It will not restart until it cools down again. Load or no load doesn't affect it. I've pulled all of the IP's, inspected and cleaned them, made sure that they were seated correctly in the rack when reinstalling, etc... Decently good on that front

Here's the kicker. When it's cold, the rack has the normal amount of tension on it(I have a few 803A's), and will default to the clockwise position without the shut off solenoid connected. However, when it's warm, it has no tension on the rack whatsoever, and therefore will not spring clockwise in its normal resting state. When it cools off, the tension will return and the gen will restart. When it starts hunting, you can disconnect the cut off solenoid and feel the lack of tension on the rack well before it dies out, although there is still some tension left toward the counter clockwise position(i.e. you can shut it off).

This is definitely not the cleanest set that I own, and there was quite a bit of corrosion when I peered down the IP Ports, but the rack looked corrosion free(the little bit I could see of it). I was ~trying to avoid digging in to the cover on the front, but I can't think of anything else to do without yanking it.

FWIW, Not a single fleck of paint had been knocked off any of the bolts/nuts, injectors, etc.... so it looks as if no-one was ever in to this thing.

I also know about the droop settings, and was thinking to start exploring that as an option before I pull the front cover. Then I ran across this thread and seemed very similar to what I was experiencing, but with no answer. So I posted in here. If you guys want me to start a new thread, I can.

Thoughts? and as always, Thank you.

Justin

If I recall the problem was the injection pumps. The unit had been setting so long I assume there was corrosion or chemical buildup preventing fuel getting thru when it warmed up. I never tore them down and soaked them as suggested, just kept starting and running it until they cleaned themselves. Each time I cooled and restarted, it ran a little longer until the unit just continued to run.

 

[justinn]

If I recall the problem was the injection pumps. The unit had been setting so long I assume there was corrosion or chemical buildup preventing fuel getting thru when it warmed up. I never tore them down and soaked them as suggested, just kept starting and running it until they cleaned themselves. Each time I cooled and restarted, it ran a little longer until the unit just continued to run.

Thank you for the reply! I am glad you got it fixed.

In my case, I suppose I need to tear down the front so I can access the linkage for the fuel supply/governor/rack.

Thanks again!
Justin

 

[CallMeColt]

Seems the original poster got his machine going, but here are some things that I would have also tried for others that may find this thread down the road;

-Confirm there was no obstructions in the fuel return lines from the injectors. On smaller Yanmar engines, I have seen them kinked, and after long run times, the injector starts putting more fuel than needed in during injection because the return line is backed up. Not much, if any comes out of them so it takes a while for the strange RPM issue to happen.

-Prime the system with ATF, start the engine so it will run for a min & get it all in the injectors as well, then shut it off & let it sit. This has worked wonders and loosening up cranking injection system parts from sitting for a long time. Be ready to run it under load after you get diesel back in though, so any crud it purges gets burnt out!

 

[justinn]

Seems the original poster got his machine going, but here are some things that I would have also tried for others that may find this thread down the road;

-Confirm there was no obstructions in the fuel return lines from the injectors. On smaller Yanmar engines, I have seen them kinked, and after long run times, the injector starts putting more fuel than needed in during injection because the return line is backed up. Not much, if any comes out of them so it takes a while for the strange RPM issue to happen.

-Prime the system with ATF, start the engine so it will run for a min & get it all in the injectors as well, then shut it off & let it sit. This has worked wonders and loosening up cranking injection system parts from sitting for a long time. Be ready to run it under load after you get diesel back in though, so any crud it purges gets burnt out!

Thank you sir.

I removed the entire accessible parts of the fuel system(hard lines, soft lines, IP's, fuel tank, etc...). Inspected and blew out all hard lines and soft lines, replaced the return line all the way to the tank. Primed the system and had a steady stream of fuel out of the return line(even while the issue is happening). When cold, it fires right up. Removed all of the IP's and cleaned them up, lubed, and reinstalled(2 of them were not as smooth as butter when I pulled them out). Used a separate fuel tank with Sea Foam and Diesel in it(stupid well nut was leaking).

I pulled the front cover today to inspect the governor mechanism and there was some questionable corrosion/rust on parts that should have had any. Seemed like there was a slight bind on the rack(maybe due to rust), but I cleaned it up and it seems to moving more smoothly now. I am closing everything back up now, so I will keep you posted. If this doesn't do it, I will definitely try the ATF route. Straight ATF?

Justin

 

[Guyfang]

I would use the ATF in the crank case also. SOP when a unit came back from down range. Let the oil out, fill the engine up with ATF and let it run a half hour. Drain the ATF and change the filter. Add cheap oil, run it a few hours, drain it and new filter. Did wonders.

 

[justinn]

I would use the ATF in the crank case also. SOP when a unit came back from down range. Let the oil out, fill the engine up with ATF and let it run a half hour. Drain the ATF and change the filter. Add cheap oil, run it a few hours, drain it and new filter. Did wonders.

I will try it!

The problem still persists.... The fuel rack is sticking in its forward(no fuel) position when it heats up. It appears that the clearance(possibly to one of the IP's) tightens up with heat and creates drag on the entire rack. I am able to go in through the governor adjust hole in the front cover and push it back, and it will fire right back up, but continue with the hunting, unless the Gen is cold. So I think I have narrowed it down to either some REALLY sticky IP's, or some sticky/dragging linkage. There is some corrosion/rust toward the #3 and #4 IP's, but I can't see clearly back there. I'll go pick up the ATF in the AM, and swap it out... that should help to knock off some of the crusty stuff as well. If that doesn't take care of it, I think I'll be going back into the front cover to see where it might be binding. Good news is that I left all of the bolts out of the radiator support/duct/fuel tank cover this time! Wish me luck!

The other thing I forgot to note... by the time I get in there to inspect anything, the darn thing has cooled off enough that there is no drag on the rack at all...

Justin

 

[CallMeColt]

Thank you sir.

I removed the entire accessible parts of the fuel system(hard lines, soft lines, IP's, fuel tank, etc...). Inspected and blew out all hard lines and soft lines, replaced the return line all the way to the tank. Primed the system and had a steady stream of fuel out of the return line(even while the issue is happening). When cold, it fires right up. Removed all of the IP's and cleaned them up, lubed, and reinstalled(2 of them were not as smooth as butter when I pulled them out). Used a separate fuel tank with Sea Foam and Diesel in it(stupid well nut was leaking).

I pulled the front cover today to inspect the governor mechanism and there was some questionable corrosion/rust on parts that should have had any. Seemed like there was a slight bind on the rack(maybe due to rust), but I cleaned it up and it seems to moving more smoothly now. I am closing everything back up now, so I will keep you posted. If this doesn't do it, I will definitely try the ATF route. Straight ATF?

Justin

Just because you are getting fuel out the end of the end and back at the tank, doesn't mean the small length from the injector(s) to the T, or even the nipple in the T, doesn't have an obstruction. If you think about it, old fuel may settle in the 1 inch or so. After years, diesel will get nasty when it is not in a large amount. Again, this was kind of a general idea. If you replaced all the lines, you are not having this issue unless it is in the injector itself.

That rust I would for sure think is a problem. I'd spray it with something, somehow to clean it up. I'd probably use BP Blaster, or something that will help break the rust up. Then, as suggested by GuyFang, ATF. ATF works wonders in cleaning stuff up.

As far as ATF in the fuel system... it's just oil. Diesel, while formulated different, is just an oil. So, it will run the engine. It will not run it well. But, the idea is because ATF is a detergent, getting it in everything & then letting it sit, it will loosen & break everything up.

I like GuyFang's suggestion of putting some in the crankcase & running it a but to slosh around and get crap out. I may just do that. I have a unit I have abused quite a bit. Over 700hrs I put on it now.

 

[CallMeColt]

Have you removed the injection pumps? Do it one by one, it will be easier.

I made this video to show details, though you probably know this with how much you have looked.

 

[justinn]

Just because you are getting fuel out the end of the end and back at the tank, doesn't mean the small length from the injector(s) to the T, or even the nipple in the T, doesn't have an obstruction. If you think about it, old fuel may settle in the 1 inch or so. After years, diesel will get nasty when it is not in a large amount. Again, this was kind of a general idea. If you replaced all the lines, you are not having this issue unless it is in the injector itself.

That rust I would for sure think is a problem. I'd spray it with something, somehow to clean it up. I'd probably use BP Blaster, or something that will help break the rust up. Then, as suggested by GuyFang, ATF. ATF works wonders in cleaning stuff up.

As far as ATF in the fuel system... it's just oil. Diesel, while formulated different, is just an oil. So, it will run the engine. It will not run it well. But, the idea is because ATF is a detergent, getting it in everything & then letting it sit, it will loosen & break everything up.

I like GuyFang's suggestion of putting some in the crankcase & running it a but to slosh around and get crap out. I may just do that. I have a unit I have abused quite a bit. Over 700hrs I put on it now.

Agreed on the return lines. Almost all of the gen's I have, that's usually 1st on my to do list, especially if they've been sitting a while. I replaced 100% of the return line fuel system and T's, and all filters in addition to blowing out all of the pressure(high and low) hard lines. I have seen some crazy gunk come out of those lines before...

*edit* I also cleaned out the return line side of the injectors with a healthy dose of WD40 and a piece of nylon filament. They were all super clean(especially compared to the ones that are gunked up... stuff turns to tar if it's been sitting a while).

I sprayed everything I could into the governor chamber to try to loosen up the rust. It's an 803, so getting to the back 2 cylinders is nigh on impossible, and I just soaked it the best I could. I will try a couple quarts of ATF in the crankcase today to try and dislodge what might be causing the drag. Probably drop a few oz's of Sea foam in there as well, for good measure. I had it running on sea foam yesterday when I called it quits for the day, so it's been soaking the entire fuel system overnight just for good measure. The drag on the rack is definitely caused by the crankcase side of the system, but I wanted to make sure everything was spic and span on the fuel delivery side also. Like ATF, the engine will run on sea foam, just not well.

I will keep everyone posted, and thanks again for the help and suggestions guys. Usually I can figure these units out pretty quickly, but this one required quite a bit of troubleshooting thus far!

@CallMeColt It was your video that I watched prior to pulling the front cover to see if I even wanted to tackle it in the first place! Thanks for that! Combined with the TM, once I got in there, it was a familiar old friend!

Justin

 

[justinn]

ATF and Sea foam in crankcase complete. Ran it for about 30m, then dumped it out, refilled with 15w40, hooked her up to a load, and let her rip....

Same issue.... dang it. It'll take 13kw loads all day long as long as it doesn't swing too far south and trip it on LOP. In my infinite frustration, I started making changes to the droop and backed out the bolt so far it popped the spring off! Luckily, I never bolted everything back down before reinstalling the last time. I now have it all ripped apart again, and will probably end up pulling the entire governor/rack system out. It has to be something relatively simple as it's all mechanical. This one has truly stumped me fellas.... The front is all torn down and everything appears in order(i.e. nothing is out of place or bent that I can see). It sure seems like governor issue, but the system is so simple that I just can't believe that can be the culprit. I attached a video with the droop cranked down about 80%, so the frequency was much higher. With it backed out, it's a much softer frequency, but the swing is still there. you can see when it loads up again to swing to a higher rpm it bellows some smoke.

https://youtube.com/shorts/neHI-jKfZhg?feature=share

 

[justinn]

ATF and Sea foam in crankcase complete. Ran it for about 30m, then dumped it out, refilled with 15w40, hooked her up to a load, and let her rip....

Same issue.... dang it. It'll take 13kw loads all day long as long as it doesn't swing too far south and trip it on LOP. In my infinite frustration, I started making changes to the droop and backed out the bolt so far it popped the spring off! Luckily, I never bolted everything back down before reinstalling the last time. I now have it all ripped apart again, and will probably end up pulling the entire governor/rack system out. It has to be something relatively simple as it's all mechanical. This one has truly stumped me fellas.... The front is all torn down and everything appears in order(i.e. nothing is out of place or bent that I can see). It sure seems like governor issue, but the system is so simple that I just can't believe that can be the culprit. I attached a video with the droop cranked down about 80%, so the frequency was much higher. With it backed out, it's a much softer frequency, but the swing is still there. you can see when it loads up again to swing to a higher rpm it bellows some smoke.

https://youtube.com/shorts/neHI-jKfZhg?feature=share

btw, that's running off of a jerry can with diesel and sea foam in it... so I took everything factory out of the equation sans fuel pump, injectors, IP's and governor system. The pump tested good, but I am to the point, I may throw a couple parts at it for testing. I have a few spare gen's, but would rather not tear them apart just to test this one....

 

[CallMeColt]

ATF and Sea foam in crankcase complete. Ran it for about 30m, then dumped it out, refilled with 15w40, hooked her up to a load, and let her rip....

Same issue.... dang it. It'll take 13kw loads all day long as long as it doesn't swing too far south and trip it on LOP. In my infinite frustration, I started making changes to the droop and backed out the bolt so far it popped the spring off! Luckily, I never bolted everything back down before reinstalling the last time. I now have it all ripped apart again, and will probably end up pulling the entire governor/rack system out. It has to be something relatively simple as it's all mechanical. This one has truly stumped me fellas.... The front is all torn down and everything appears in order(i.e. nothing is out of place or bent that I can see). It sure seems like governor issue, but the system is so simple that I just can't believe that can be the culprit. I attached a video with the droop cranked down about 80%, so the frequency was much higher. With it backed out, it's a much softer frequency, but the swing is still there. you can see when it loads up again to swing to a higher rpm it bellows some smoke.

https://youtube.com/shorts/neHI-jKfZhg?feature=share

That's a frustrating one. I'm sorry. We all have one project like that. Beyond me! I'm sure, like you are guessing, it's something stupid. I wonder if at some point, an injection pump was removed improperly and the rack is ever so slightly bent, causing just enough drag & when it's hot it gets more upset about it.

 

[Ray70]

Maybe also take a look at the levers on the IP's. When installed they just barely clear the underside of the block without rubbing. If one of the levers got bent up just a tad, it may be rubbing ever so slightly when things expand.
Excessive shims under the pumps further reduces the clearance between lever and block.
If you have to take the cover off again, try looking in there with a flashlight and maybe a borescope type inspection camera to see if you can see all 4 pump levers.

 

[justinn]

That's a frustrating one. I'm sorry. We all have one project like that. Beyond me! I'm sure, like you are guessing, it's something stupid. I wonder if at some point, an injection pump was removed improperly and the rack is ever so slightly bent, causing just enough drag & when it's hot it gets more upset about it.

Also Checked for this.... rack is actually in good condition, buttttt, I think 2 of the injection pumps may experiencing drag when hot. I cranked up the Ultrasonic Cleaner to 70C and let them bake in there for over an hour. There was slight drag on #2 and #3 compared to zero drag on #1 and #4. It's ever so slight, but it's there. I will button it all back up tomorrow and fire it off to see if another hour in the ultrasonic affected them. If not, I will just pick up 2 IP's and test those.

This one has been a real headache, but I refuse to accept defeat!

Again, I thank everyone for the ideas and the help!

Justin

 

[justinn]

Maybe also take a look at the levers on the IP's. When installed they just barely clear the underside of the block without rubbing. If one of the levers got bent up just a tad, it may be rubbing ever so slightly when things expand.
Excessive shims under the pumps further reduces the clearance between lever and block.
If you have to take the cover off again, try looking in there with a flashlight and maybe a borescope type inspection camera to see if you can see all 4 pump levers.

Thanks Ray,

I also thought initially this may have been the issue(especially with the corrosion that was present in some ares). When I reinstalled them this time, I measured out the drop in the IP from the block to when I could slide the rack, and they all seem to be a touch over 1.5mm(not an exact number, but just my rather uncalibrated eyeball measurement). I also, very painfully, stuck my finger in the hole and felt underneath that part of the block for any scale that may have been hindering movement. Nothing substantial. I will keep everyone posted for tomorrow when I fire it up. I don't have any parts gens as I am too damn stubborn to let one defeat me. 8 generators currently, and 7 of them are tip top...

With the cover off, I had line of sight on the first 2 IP's only.... I was hoping to be able to reposition to look at the other two, but I think unless I pull the linkage out, that ain't happening' LOL I do have a boroscope, and now that you mention it, I just should have used that! Dang it! If push comes to shove, I should be able to route it in through the droop adjustment hole.

Justin

 

[justinn]

Here is the latest update. I am 96% sure that it is the drag on the IP's when they heat up. I am pulling the 2 questionable ones out today and disassembling/clearancing them. I will then test in the ultrasonic again as I did last time. This is the first time I have ever seen the IP's drag when heated up. If they weren't so expensive, I would just buy 2 new ones, and rebuild these to keep as spares.

Justin

 

[justinn]

Does anyone have a diagram of just the IP disassembled? I perused the TM, but I didn't see the lower assembly diagram. I am sure I can just "wing it", but it would be easier if I had that diagram....

I cleaned those 2 up with some 2k grit and have it in the ultrasonic now....

Justin