MEP-804A Smoke, what is the cause?

[Evvy Fesler]

My genset makes constant smoke. I’ve read up on smoke and it’s quite confusing. White, blue, black… they all mean different things, but other than black the colors are quite subjective to me.
Here’s a video. Tonight it not only makes smoke, it runs rough, which it hasn’t done before. I’ve had this generator for just over a week. As always, your insights are appreciated!

-MEP-804 Smoke

Evvy-

 

[uniquify]

I don't have your particular model of generator, so take this with a grain of salt...

That smoke seemed mostly white to me. There where a couple times when it sputtered and gave out a little black smoke. It was hard to see/hear if the sputter corresponded to more cylinders firing, or fewer firing. If you take another video in the future, ttry to back up a little more so the Frequency gauge is in view.

Did it sound like it was trying to speed up when the black smoke came? If you can't tell by ear, the Frequency (Hz) gauge may give us a hint.

Did the exhaust smell like unburned fuel? I'm wondering if it was only running on a few cylinders most of the time, then occasionally another cylinder or 2 would kick in (when the black smoke appeared).

Have you checked the oil level lately? If too much fuel is coming out of an injector, it might be leaking down the cylinder walls and diluting the oil, which can cause the oil level to rise.

 

[Light in the Dark]

Does the exhaust smell sweet at all?

 

[Guyfang]

How many hours on the set? OK, answered my own question by looking at the video. What rated Freq, is the set running at? Sounded a little slow? But I wear hearing aids, that may be my problem. White smoke sounds to me like unburnt fuel. or, if sweet smell, coolant. Have you changed or looked at the air filter? Crack the injector lines at the IP, one at a time. If the engine starts to die or lose power when you crack a line, that line is providing fuel to the engine. If the engine sound doesn't change when you crack a line, then that line is not providing fuel to the injector, OR, the injector is non-op.

 

[Evvy Fesler]

How many hours on the set? OK, answered my own question by looking at the video. What rated Freq, is the set running at? Sounded a little slow? But I wear hearing aids, that may be my problem. White smoke sounds to me like unburnt fuel. or, if sweet smell, coolant. Have you changed or looked at the air filter? Crack the injector lines at the IP, one at a time. If the engine starts to die or lose power when you crack a line, that line is providing fuel to the engine. If the engine sound doesn't change when you crack a line, then that line is not providing fuel to the injector, OR, the injector is non-op.

Good morning to all!

The oil level is correct by both the dipstick measure and pressure gauge. It’s the first time it’s had oil since I brought it home last week. Evidently they drain all fluids for transport.

I bled out the water separator into a glass jar and a day later there isn’t any water in it. JFYI as I should’ve mentioned that earlier.

The genset is low voltage so the frequency meter doesn’t show anything. I do hear a change from laboring to unburdened idle when I let the start switch go from start to run.

I hadn’t thought of the air filter. The outer one was clean when I checked it last week. I didn’t pull the two of them out all of the way. Maybe there’s a mouse nest in there. I’ll check later today.

What does IP mean? I’m thinking Injection Point? Where it enters the block?

Thanks all,

Evvy1

 

[kloppk]

What does IP mean? I’m thinking Injection Point? Where it enters the block?

Injection Pump

 

[Ray70]

I'd start by cracking the injector lines like Guy suggested.
I think you may have a cylinder not firing ( the smoke being the unburnt fuel from that cylinder )
If you crack the lines and get one that doesn't change the engine's sound then we need to hone in on that cylinder.

Also try dead cranking it. See the the compression sounds even from one cylinder to the next or do the pulsations sound unbalanced?
Also try removing the oil cap while its running to see if you feel excessive blow by in the crank case.
And listen for any abnormal popping sounds either from the exhaust or air intake that might indicate a stuck valve.
If you remove the air cleaner and run it, any evidence of smoke in the intake, especially immediately after shut down would indicate a stuck intake valve.

 

[Evvy Fesler]

Hi Ray, Guy and all...

I'm a little tentative about this. Not your instructions... they are very clear and sensible. I'm nervous because don't have experience here. When I think about pumps I imagine pressure. Loosening connections, in my mind, is likely to cause spray or a stream of fluid, in this case, fuel. There are hot surfaces in the area. If y'all would coach me a bit more, where exactly do I loosen and by how much? Am I expecting fuel and should collect it somehow? I've attached a picture.

 

[Ray70]

No worries at all, its better to be apprehensive if unsure than take a risk of getting hurt.
The amount of fuel expected is very very small, mere drops and it is under high pressure, but because the amount is so little that the result will be just some minor drips or a small spurt. You will not get a high pressure spray by any means.
All you really need is to wipe it off with a rag. Diesel is flammable but not explosive like gasoline, you don't need to worry about explosive vapors.
You can either loosen the nut at the injector ( without fear of fire or explosion )
Or you can loosen the upper nut at the injection pump.
Just do 1 at a time and wipe off the drips after you tighten each line.

 

[Evvy Fesler]

Great - thank you. So in my picture, I have two places to loosen and it would seem to me that the most accessible is the bubble on the right. I figured out that the knurled part is locked - probably it's an adjustment. I suspect I'll learn more about them later. :0)

 

[Ray70]

Yes, the top right square that says "Loosen here?".... Loosen it there!

 

[Evvy Fesler]

No worries at all, its better to be apprehensive if unsure than take a risk of getting hurt.
The amount of fuel expected is very very small, mere drops and it is under high pressure, but because the amount is so little that the result will be just some minor drips or a small spurt. You will not get a high pressure spray by any means.
All you really need is to wipe it off with a rag. Diesel is flammable but not explosive like gasoline, you don't need to worry about explosive vapors.
You can either loosen the nut at the injector ( without fear of fire or explosion )
Or you can loosen the upper nut at the injection pump.
Just do 1 at a time and wipe off the drips after you tighten each line.

I loosened them all, one at a time, always tightening before testing the next one. They all had pressure (see P.S. below). Only one affected engine operation and even then only slightly. The locked down fitting on the outermost right isn't locked down at all so I had to secure it to crack the flared fitting attached to it. This was the one feed that made the engine run a little differently.

The picture attempts to show that I had loosened the far left feed tube. I think I'll need a better camera to show anything useful fuel spit-wise.

I also pulled the air filters and tried running/starting and stopping. The engine doesn't make any blowback and it doesn't want to run and will stall without the filters inserted. It begins to shudder even when loosening the clamp. They are new WIX filters.

P.S. My granddaughter forbids me to enter the house smelling like diesel fuel. Grrrrr....!

 

[Guyfang]

How old is your granddaughter? I smelled for 20 years like diesel. After about a year into retirement, I came home SMELLING, (I never stink!) like diesel. My wife looked at me and smiled. "Ahhhhhhhhhhhhhh, just like the old days! I kinda miss it." she said.

I would have opened them up at the left bubble, as any trash in the Injector lines, might come out when you were doing this. But both places work. How did the engine operation change on the one line? Ray, maybe we need to look up the fuel pump pressure test procedure?

 

[Evvy Fesler]

How old is your granddaughter? I smelled for 20 years like diesel. After about a year into retirement, I came home SMELLING, (I never stink!) like diesel. My wife looked at me and smiled. "Ahhhhhhhhhhhhhh, just like the old days! I kinda miss it." she said.

I would have opened them up at the left bubble, as any trash in the Injector lines, might come out when you were doing this. But both places work. How did the engine operation change on the one line? Ray, maybe we need to look up the fuel pump pressure test procedure?

@Guyfang, Guy - she's 10-years old. He grandfather is home from doing volunteer work (Red Cross) at the Raleigh Military Entrance Processing Station (MEPS). He convinced her that diesel smell makes the Oatmeal-Craisin cookies we're going to bake later taste better!

I loosened each one again at the injector as you suggested. This time I wrapped a rag around the flare nut (presumed) and actually pulled the tube away from its seat. None of them affected engine operation. Odd?

I took pictures of behind the fuel injection pump, but they don't reveal anything to me. Maybe they will for y'all?

 

[Guyfang]

You need to have talk with your granddaughter. Grandpa's are normally right about EVERYTHING. Diesel makes everything better! In a few years, if you all are looking to marry off your granddaughter, I have a grandson who is 4, (in two days) who LOVES any kind of construction equipment, tractors, trucks and all that is mechanical. Maybe we can make a deal?

Huhh. The IP looks like its been changed, to me. But I am old. Ray, what you think. I learned, (about 30 minuets) back in 1985, how to fool with similär IP's, like this one. I seem to remember, (maybe) that the rotation of the IP's, in the pump body itself, can advance or retard the IP pop off timing. The fact that the right side of the IP is loose, kinda bumped my memories. But I am asking for conformation here. If so, and if the IP has been changed before, take a look at the IP's where they go into the IP body and see if someone has maybe moved them. Marks on the nut sat the bottom?

Have the fuel filters and water separator been changed/or looked at?
Should we maybe check output of the fuel pump?

Dont think air is a problem, as Evvy has broken the injector lines up at the injectors, and that rules out air in the system now.

 

[Ray70]

When you loosened the lines, were you getting fuel spitting out of each line after you loosened them?
It sounds like you only noticed a difference when loosening one line, did the machine just stumble a little or would it have died if you loosened that one line and left it loose for a couple seconds?
Seems crazy that you would have just one cylinder firing, but anything is possible!
If possible, could you post a video of the machine starting from a cold start?
Guy, this will be a new endeavor for me... I know a little about the 004/005 pumps, but my first time on an 804A as far as IP but we'll get through it!

 

[Evvy Fesler]

@Guyfang Guy - your proposal has potential! And yes, Grandpa's are the best!

I bled the water separator into a glass jar and the next morning it didn't show signs of water. I did not change the filter. I will do that if y'all think I should?

@Ray70 Ray - C'mon in, the water is warm! I loosened each flare nut completely and pulled the tube back a little. No difference for any of them the second time around. It's almost as if they are getting fuel from the other line that goes across the top of the injectors. Is that a bleed-off line that sends excess fuel back to the fuel tank? I'm just saying that to overemphasize the oddness of this. Under no circumstances has this engine stalled.

 

[Guyfang]

@Guyfang Guy - your proposal has potential! And yes, Grandpa's are the best!

I bled the water separator into a glass jar and the next morning it didn't show signs of water. I did not change the filter. I will do that if y'all think I should? If its a fuel delivery problem, pre-IP, that might help. But troubleshooting is where you go logicaly at a problem, excluding one thing at a time, until you hit the jackpot. I would.

@Ray70 Ray - C'mon in, the water is warm! I loosened each flare nut completely and pulled the tube back a little. No difference for any of them the second time around. It's almost as if they are getting fuel from the other line that goes across the top of the injectors. (that line is low pressure. Its a return line. So no, you can not get fuel from it to the Injectors) Is that a bleed-off line that sends excess fuel back to the fuel tank? I'm just saying that to overemphasize the oddness of this. Under no circumstances has this engine stalled.

Open to read comments.

 

[Evvy Fesler]

Open to read comments.

I can certainly change the filter. I should have by now anyway just to establish a baseline if nothing else. I can try capping off one line at a time and attempting to start it and see how it runs (if it'll start). There is fuel control in that when I switch from 60 Hz to 50 Hz, it slows down a bit.

 

[Guyfang]

PLEASE do not switch it from 50 to 60m hertz while running!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Bad things can happen!!!!