New to Mep-803A ownership general questions

[Guyfang]

Reminds me of two guys I found working on an old gasser, in a trailer, with the flaps down, cause it was cold. Lips were blue, and they could hardly talk. Not good for your future.

 

[Ray70]

As Guy and LITD have mentioned, there is something wrong with the start-up.
It seems to crank a little to quickly and take too long to light off.
It sounds like there may be a compression issue on 1 or more cylinders, but first you need to get it to run within the operating RPM so you can do more extensive testing.
I think you need to get it set up with a Hz meter on the courtesy outlet, fire it up and see where you're at.
It will rev quite a bit higher that what was in the video, so you may not be as far off as you think, but if you can't lower it and can't shut it off from the Fuel solenoid there is definitely a problem.
To that point I once had an 802 that had an incorrectly assembled Fuel lever lever, the end that is inside the block attached to the solenoid. That machine also could not be shut off from the solenoid. The 2 pieces that bolt together are supposed to be locked in position by a flat on the end of the shaft, but someone misaligned the 2 interlocking flats.

 

[Ericsdoomsdaygenerator]

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This just looks so bad.. Unless i don't know what i'm looking at; (which is partially true). Tell me.. is it ever normal to see an inferno come out of cylinders like that? looks like two cylinders arn't getting fuel and the other two are also doing crazy not right stuff..

With it running that rough does it really seem like i'll have time to even check the HZ out before that thing just kills itself..
As a total novice doing this, i celebrated too early in my mind. I never thought it would start at all with compression problems. So now i'm bummed realizing i probably wasted a whole bunch of my time and money. I can invert the fuel lines and mock up two injectors outside the engine to see what they spray like when I crank. Ill probably use that method to check all the fuel pumps and inectors..
Feeling defeated, hmm,.

 

[Ericsdoomsdaygenerator]

I would remove the cast iron exhaust manifold and inspect the smoke color and air temperature of each cylinder.

Here is an 802 I had recently worked on. The cylinder nearest the radiator was not getting fuel. Exhaust color was different, and the air coming out was cold.

Before eval: https://www.youtube.com/shorts/pw25Md5yITE

With manifold removed: https://www.youtube.com/shorts/GlNmtkmIo_c

After fixing metering pump near radiator: https://www.youtube.com/shorts/jUN6FNbjmdA

You will get there.

My set seems to be going 2x or 3x the speed of yours with or without a misfire. So frusterating i don't understand how my pumps can be overfueling like they are.

 

[Light in the Dark]

Well the injectors will limit the amount of fuel going into the cylinder, the pump can push as much as it wants, its limited by the orifice sizes in the injector. Your engines definitely got some gremlins at the present time (two do have white smoke at start). I think you may want to pull the injectors and see what they are doing under 'run' conditions... see if you are getting an atomized spray or just raw fuel dumping in at volume.

The governor doesn't appear to be doing its job either. Im glad you took this out of the bus for further eval.

 

[Ericsdoomsdaygenerator]

There is an allen key adjustment in the gearcase cover on the governor assembly;, Maybe someone before me had messed with that... What does that do? what does clockwise do, and vise versa? Anybody know?

 

[Light in the Dark]

That is the droop adjustment. That changes the rate at which the governor plays catchup on load shifts. I don't know if that can be messed with enough to display what you have. You may end up needing to pull that gear cover to inspect the governor linkage and all moving parts in there.

 

[2Pbfeet]

Making progress!

I agree with @Light in the Dark that I think it is time to pull your injectors and check for function and spray patterns. Two of your cylinders appear not to be igniting. That will cause an under speed that the governor will react to by providing more fuel (too much fuel, in fact). That accounts for the flames in the two cylinders that are igniting.

With luck the spray patterns/functioning on the injectors may account for the unburnt fuel/grey smoke.

All the best,

2Pbfeet

 

[Ray70]

Can't wait to see what you find with injectors out. I wonder if the flaming cylinders have injectors stuck open and just dumping fuel into the cylinders.

 

[Ericsdoomsdaygenerator]

Well, I think i found an obvious problem. Could anyone tell me, what is the injector hold down clamp torque spec?.. after inspecting the pulled injectors, its obvious from all the improperly fueled start up attemps, they all appeared to be black and tips filled with soot.

 

[Ray70]

Did you test them by attaching the fuel lines with them positioned off to the side?
I doubt the soot is the root cause, but rather the effect of the real problem.
I'd check to see if you have a deeper mechanical problem with the injectors before cleaning off the soot and reinstall.
Or better yet, clean them, then test before installing, just to try to verify root cause.
You can disassemble and clean the pintles and the 4 holes in the nozzles.
You should be getting short 4 radial spray bursts out of the sides of the tips.
any dripping, squirting , fuel stream etc. indicates a bad injector.

 

[Ericsdoomsdaygenerator]

Did you test them by attaching the fuel lines with them positioned off to the side?
I doubt the soot is the root cause, but rather the effect of the real problem.
I'd check to see if you have a deeper mechanical problem with the injectors before cleaning off the soot and reinstall.
Or better yet, clean them, then test before installing, just to try to verify root cause.
You can disassemble and clean the pintles and the 4 holes in the nozzles.
You should be getting short 4 radial spray bursts out of the sides of the tips.
any dripping, squirting , fuel stream etc. indicates a bad injector.

Skip to like 40 secs. in Slo mo camrea is amazing..

So the injecotrs were not shooting like that right off the bat,, i had to clean them... Maybe this whole problem became because i didnt have them tight enough and they leaked and i lost compression..???


I had to crank over like 5 times before they did that tho,, and for some reason cylinder one happens to be not playing its part and unfortunately i cant test all 4 at once because of the way the lines have the bends.. how is that spray pattern??

 

[Mullaney]

Skip to like 40 secs. in Slo mo camrea is amazing..

So the injecotrs were not shooting like that right off the bat,, i had to clean them... Maybe this whole problem became because i didnt have them tight enough and they leaked and i lost compression..???


I had to crank over like 5 times before they did that tho,, and for some reason cylinder one happens to be not playing its part and unfortunately i cant test all 4 at once because of the way the lines have the bends.. how is that spray pattern??

.
I see 4 bursts, One from each injector...
Looks good to me.

 

[Ericsdoomsdaygenerator]

the three mocked up injectors look great, now cyclinder one injecion pump has no fuel coming from it.. (wack a mole with these fuel issues)

 

[Ericsdoomsdaygenerator]

I have all 4 injectors spraying like in the slo mo video now. So i put it back together.
I should have left them there in mid air to continue to test until i figure out how to turn down the volume of fuel.
Still The machine , with all 4 incjectors firing like in the slow motion video. It wants to race itself well past normal operating range and will not shut itself off with the S1 or the emergency turn off. (well it might, but it should not take 2-3 minutes to shut down.)
I didn't touch the governer assembly at all behind the front gearcase. but now i see no other variable to mess with; maybe someone messed with it before me. Is it a possiblity a spring in place may have just gotten weak and the balance is just a wee bit off. ?

next move is to pull the gear case cover AGAIN.. and look around and take photos and videos of springs and rack function. Tham again i can verify with the boroscope all the injector pump arms are still in the rack, which i'd bet my life on at this point considering how many times i've pulled and reinstalled them.

3 Main questions/ Big new observations.

Firstly let me admit; I can recall a moment whereas i had put an alot of force on the frequency cable accidently when i was freeing up the engine. I'm wondering if it is possible i bent the speed spring , by accidently wacking the frequncy cable!

1) What is taking place to "Meter the amount of fuel"? if i understand correctly it is how far the metering arms move. So It would make sense to back out the idle screw to keep the run lever from ever letting the rack get so far to the right.
I'll try that before pulling the gearcase cover.

2) Could i try to plug the oil jet holes behind the gearcase cover to try to run the engine with the cover off to see what is going on in there??

3)

see the video and notice the stop solenoid has no gap in the slot where the knob is when in run position. and appears to pull the lever to the MAX setting even thou the fuel knob isnt binding in any way? That may indicate the governor problem or A BENT SPEED SPRING??

1-12.9 Governor Control System. 1-12.9.1 The Governor Control System (FIGURE 1-10) includes the FREQUENCY ADJUST control, mechanical engine governor, engine fuel pump rack, and fuel solenoid. 1-12.9.2 The mechanical engine governor is housed under the engine gear cover and moves the fuel pump rack, changing fuel delivery of the injection pumps in proportion to engine load. The governor is a flyweight type, with the weights mounted on the engine camshaft gear. The force of the flyweights is transferred through a thrust sleeve and collar to the governor lever, and balanced against the tension of the governor spring, which is stretched between the governor lever and the speed adjustment lever. Engine speed and generator output frequency are increased by increasing the tension on the main governor spring. Droop is adjusted by varying the location of the governor spring’s mounting to the governor lever, effectively varying the strength of the spring. 1-12.9.3 The governor uses one lever for fuel shutoff and the other for speed adjustment. The shutoff lever is operated by the fuel solenoid in an energize-to-run configuration (fail safe). The speed adjustment lever is moved by a vernier control cable from the FREQUENCY ADJUST control of the set and provides an adjustment range of + 3 percent of rated frequency at rated load.

 

[Ray70]

Injector sprays look good to me.
You may be on to something with the governor.
The way the rack works is when not running and the fuel solenoid retracted, the spring on the rack moves it fully rearward.
This rotates the pins on the metering pumps to the full fuel flow position ( wide open )
As soon as the engine starts the governor takes over and brings the rack into the correct position to achieve the RPM based on the throttle position.
The connection between the governor and rack is a spring, this allows the fuel solenoid to push the rack forward, rotating the metering pump pins and closing off the fuel flow, killing the engine, despite the governor trying to increase fuel due to the engine slowing down.

 

[Ericsdoomsdaygenerator]

Refrencing another Steel soilders thread about another unit that wont shut itself off; refrences a particular roatation in regard to rebuilding the Injector pump seperate of the rotation placed in the block. Maybe i rebuilt the Injector pumps wrong.

 

[2Pbfeet]

the three mocked up injectors look great, now cyclinder one injecion pump has no fuel coming from it.. (wack a mole with these fuel issues)

While I suspect something is off on your governor or rack, or possibly timing, I do wonder if it would be worth your while to clean your fuel lines downstream of the final filter. Cylinder 1 not firing either means the injector just plugged, or the pump isn't coming up to pressure. Since the pump and injector were functioning for the first video, I'm inclined to think that the injector got some debris in it.

Great slow motion videos!

An older, wiser diesel mechanic once said to me that working on and around diesel injection lines needed to be "cardiac surgery spotless". The tolerances in injectors are pretty darn tight.

All the best,

2Pbfeet

 

[Ericsdoomsdaygenerator]

Cylinder one was not firing becasue i overtightened the top of the injector pump. I'm still suspect of misbuilding the injection pumps because they "fire" but they don't turn down or meter the fuel.. and there seems to be no detailed info online as to the order of operations to line up the holes and punchouts of the injector internal plungers. I brought this question up earlier with a few pics. That's what i need to find out to before i do anything else.

 

[Ray70]

I know several folks here have disassembled and rebuilt their metering pumps and documented their work.
The issue will be finding those threads because the search function will only get you so deep into the details.
If non of them happen to read this, you may need to hunt around here on the forum. There probably aren't any documents showing this info because the metering pumps are meant to be replaced, not repaired, but several members here have done it successfully.

As for the injector, are you thinking that overtightening the top was causing it to not fire? Is that a theory or have you confirmed it by loosening it? That doesn't sound right to me, unless you somehow cranked it down and disrupted the shims that set the pop pressure. Or perhaps I'm misunderstanding what you mean.