MEP 002 running rough

[ragnar]

Hello all,

I gave my parents one of my MEP units several years ago to use during power outages. It has received intermittent use over the years, but I can’t vouch for how much of a load was on it when it was used. It has received yearly oil changes but little other service in that time. I visited recently to check on it, change the oil, etc. When I fired it up for the first time, it ran normally for a few seconds, and then began a rhythmic revving and lulling of the engine. It literally sounded like someone was making the engine rev for a second and then idle. I flipped the breaker and the HZ needle jumped in tandem with the revs. I then plugged in two hair dryers to exercise the unit (I had rigged up 2x 20A outlets, one off each of the generators hot legs for 240V power). It ran slightly better with each leg having a hair dryer load, but there was still some rhythm to the engine. I ran it with one hair dryer (only one leg getting power) and it may have been a bit smoother. Any thoughts on what may be causing this?

 

[Guyfang]

This could be a fuel restriction problem. Could also be the linkage at the K5. Will the linage move corectly? Test the fuel pumps IAW the TM.

 

[jamawieb]

Sounds like old fuel or water in the fuel.

 

[ragnar]

thank you both - will start with purging the fuel and changing out fuel filters and see what that does.

 

[Chainbreaker]

Sounds like it might be hunting. If so, this thread might help you with verifying the governor setting adjustment.

 

[robertsears1]

I have had a 003 for probably 15 years now. I noticed that the strainer inside the fuel fill was slow to let the fuel through. You can twist and remove the whole strainer assembly. Mine was coated about 95%. I tried several things and damaged the fine screen cone with a pressure washer. I found that carb cleaner in the can melts that coating right off. The tank was also nasty and I was so embarrassed, I didn’t take any pictures. Carb cleaner will also help that out. It works better if the tank is removed. You should also look at the three fuels pumps. If you remove the bottom of each pump, you will see a magnet and screen that also responds well to carb cleaner. I think a 5/8 or 3/4 fits the nut on the bottom, turn it clockwise looking down from the top. I also probably changed out the two fuel filters and water separator, again too embarrassed to take a picture. May not help your surging, but sure will not hurt anything. There is a spring up on the the right front side just behind the fan that has to do with the throttle cable. Mine slipped down one time and had to be reattached. It was probably because I was doing the wrong thing before shutdown and slowing the engine down. Do not do this, set the throttle at 60 or 61 hz and leave it alone.
Robert

 

[PJL]

Had a similar issue with a Baldor light tower. Turned out water in the fuel had ruined it. I plumbed in a spare fuel can of new clean diesel and it ran perfectly. This was after changing out filters and one bad injector.

 

[Mullaney]

I have had a 003 for probably 15 years now. I noticed that the strainer inside the fuel fill was slow to let the fuel through. You can twist and remove the whole strainer assembly. Mine was coated about 95%. I tried several things and damaged the fine screen cone with a pressure washer. I found that carb cleaner in the can melts that coating right off. The tank was also nasty and I was so embarrassed, I didn’t take any pictures. Carb cleaner will also help that out. It works better if the tank is removed. You should also look at the three fuels pumps. If you remove the bottom of each pump, you will see a magnet and screen that also responds well to carb cleaner. I think a 5/8 or 3/4 fits the nut on the bottom, turn it clockwise looking down from the top. I also probably changed out the two fuel filters and water separator, again too embarrassed to take a picture. May not help your surging, but sure will not hurt anything. There is a spring up on the the right front side just behind the fan that has to do with the throttle cable. Mine slipped down one time and had to be reattached. It was probably because I was doing the wrong thing before shutdown and slowing the engine down. Do not do this, set the throttle at 60 or 61 hz and leave it alone.
Robert

.
Too bad you don't have any pictures, but it sure sounds like you found some hidden stuff that really needed help!
Any particular brand of Carb Cleaner?

 

[robertsears1]

It was Valvoline carb cleaner mostly because it was BOGO at Advance Auto. I used some other brands and they all seemed to melt the residue right off.

Robert

 

[Mullaney]

It was Valvoline carb cleaner mostly because it was BOGO at Advance Auto. I used some other brands and they all seemed to melt the residue right off.

Robert

.
Thanks! We have 3 choices all within a quarter mile of here. Advance has the one old guy who actually has a brain rather than using the computer. Because of that - they are my default car parts place.

I think I will grab a few cans of Valvoline and see how it might work for cleaning the tank valve on my M936.
Thanks for the lead!

 

[ragnar]

All,

thanks for your responses. So far I have drained all the fuel, cleaned the fuel strainers, cleaned the fuel pumps, changed the fuel filters, and refilled with diesel with Lucas injector cleaner mixed in. The inside of the fuel tank is definitely a problem - there was quite a bit of rust sediment in the bottom. Not sure what the best way is to tackle that, but anyway….. After all this I fired it up again and while the engine definitely started easier and ran better, it is still revving at intervals when there is no load applied. Once I apply a load (1000W - 2000W) it stops revving. But once I turn all the loads off, the Hz jump and the engine starts revving at intervals again. (A more accurate description is that it is ‘dropping’ and not ‘revving’, as the baseline RPMs seem to go up and then for shorter, rhythmic intervals they drop). Most of the time the generator does not appear to be adjusting Hz on its own properly as I add and remove loads - I frequently have to tinker with the throttle after adjusting loads to get it back to 60. And then when I remove all loads, the revving starts again.
Can it be an injector problem if it behaves properly with a set load? I assumed the governor might be the culprit so I tried the adjustment process in the TMs (setting high and low speed and sensitivity), but am pretty sure I’m doing something wrong there. Is the goal to limit the low and high speeds the generator can run at? I turned the high speed adjustment screw all the way to the right but that doesn’t seem to limit how high the engine can rev. And tinkering with the low speed adjustment nut didn’t seem to do much either. If anyone can please explain in layman terms what and how to do here, I would be most grateful.

 

[Ray70]

Sounds to me like a couple possibilities, both pertaining to the governor and injection pump itself.
Start by pushing the fuel shut off solenoid up and out of your way.
Does the linkage arm move freely at the Injection Pump? If there is any sticking or binding at all, that is going to cause you issues with the governor sensitivity.
Also, make sure the spring loaded arm going to the IP from the governor arm is working correctly and not sticking at all where the extension / compression area is.
If that is OK, where is your spring located on the adjustment with the star wheel as far as position? I would expect you to be about 3 turns up from the bottom. If you are not even close to the 3rd notch up from the bottom, something might be out of whack.
Lowering the spring closer to the pivot point at the bottom will increase governor sensitivity and will cause hunting when not under a load if you go too far down.
Raising the spring upward away from the pivot will decrease sensitivity and stop the hunting but if you go too far the machine will tend to not stay close to 60hz as you apply a load, it would tend to droop down under a load, then rev up over 60+ when you remove the load.
I have seen 2 or more machines where the droop setting was not obtainable per the TM instructions. In one case the spring itself was bent and needed to be replaced, in the other instance the governor arm coming out of the timing cover was bent in the area near where the IP link attaches, towards the outer tip.
If possible, can you post a picture of where your spring adjustment is now?

 

[ragnar]

Thank you for the quick response. the spring loaded arm feels like it’s moving freely up and down and the governor arm seems to also move freely back and forth (although with more spring resistance). The control arm to the solenoid moves fairly freely, but perhaps not quite as well as the other two. Here is a picture of my current spring settings.

 

[jamawieb]

Everything Ray70 said above is point on. I would try raising the governor spring on the star adjustment to see if the hunting stops. I doubt its the injectors or pump. Its going to be something easy.

 

[Ray70]

I agree. I think you need to try performing the droop adjustment again. Either raise the spring to stop hunting or lower the spring to reduce the amount it droops down when a load is applied.
Keep in mind that as you change the droop setting you will also need to readjust the throttle upon start-up to correct the engine speed for the adjustment you made.
For now don't worry about the min and max screws. Just concentrate on the spring / star wheel.
If you find it is impossible to both stop the hunting and attain an acceptable droop of no lower than 58.5 hz. at full load and 61.5 at no load without touching the throttle, then something else is wrong.
Also, can you send a picture of the nut where the 2 arms are bolted together at the tip of the governor arm?
90% of the time you need to have the nut pretty much all the way out at the tip of the governor arm, making it as long as possible.
And make sure the arm to the IP doesn't rub on the side of the hole in the sheet metal where it passes through when moved through its full range of motion.

 

[ragnar]

Thanks, Ray. Will tinker with the spring today and see what I can do. Here is the pic - the nut appears to be as far out as it can be.

 

[Ray70]

Yup, that all looks correct. The spring in that shot also looks to be in the ballpark.
Maybe you should give it a bit of a workout first, then attempt the droop adjustment again.
If it has been sitting a while i am a little concerned about maybe having some gum / varnish in the injection pump that is slightly inhibiting free throttle movement. It may feel ok to you, but could be just restricted enough to cause a slightly delayed reaction to the governor weights.
A bit of a workout with that fresh fuel and the sea foam might clean it up prior to making your droop adjustment.