MEP-803 - Load testing not successful

[mesias]

Hey guys,

After all the help from this forum I managed to have this machine up and running. Without load it runs smoothly with almost no visible exhaust smoke. I have it now connected to the house electrical panel so all I needed was to complete a load test. For this I built a simple device, inspired by other members here, with a couple of 5400W dryer heat elements. This takes the genset to around 46 A or 85% of capacity.



Before this test I've always found difficult to maintain the same frequency setting every time I start the genset. For some strange reason it'a always (with no load) above or below the 60HZ line. When I applied the load of a single heat element plus the fan, the genset took it with no trouble. Just a bit of smoke, the frequency went down a couple of lines but went right back up. This is how the gauges look with this load:



The first time I connected the second heater element... the gen set couldn't take it and it bogged down. I immediately removed the load and it recovered maintaining the previous load. I tried again a few times until the genset managed to take the additional load and hold the pace for it. I played for a while adding and removing the additional load and the genset would fail sometimes and other it would take the load. Every time it could assimilate the load the frequency dropped a few lines and you can hear the engine struggling.

In the process of "bogging down" this is what I observed:

• Heavy black smoke is thrown out (this could be from the wet stacking the unit has)
• The frequency dropped all the way down and you can hear the motor almost shutting down
• The coolant spilled from the relieve hose after overflowing the plastic container

Here is a picture of the gauges at 85% load:



HERE is a video to the unit bogging down and HERE is another video of the unit running at 80% load. HERE is a video showing how the frequency drops and lags to recover after adding more load.

I'm suspecting this is related to the electrical fuel pump not copping with the demand. I read a post I needed to add a pressure gauge to test it but before spending more money in stuff I would like to hear your opinion. Here are some questions I have:

1. Is the amount of back exhaust smoke "normal"?
2. What could cause the motor to bog down like that?
3. Why the coolant was spilled while losing power?

Thank you again in advance for your feedback.

 

[Light in the Dark]

So if you have signs of wet stacking, I suggest dumping an entire can of Seafoam into whatever fuel you have in the set, and let it run at whatever the highest stable load figure is (it appears to be 80% based on the videos above, but you really should compensate the hertz adjustment back up to 60+ under this load... can you do that?), and let it rip for as long as you can stand it (or you run out of fuel). Seafoam can do wonders on cleaning up these sets under load. Just get it burning hot, clean, and steady. Ive had many sets in that Seafoam have helped go from nonperformers, to winners.

I'm not concerned about the fuel pump keeping up right now. Have you seen this run at full rated output, or is this a brand new acquisition? I think you just need to take care of the wet stacking and you will see a noticeable improvement. Just be hanging around when you do it, as it will throw out hot bits of carbon (pellet and tar) while it cleans it up.

Good luck and let us know.

Edit: Set the machine to about 61.5 hertz before you start loading, and let it eek backwards to about 60hz.

 

[mesias]

I can manually compensate the frequency and increase the Hz to be as close as possible to 60. But isn't this supposed to be controlled by the governor? I assumed once you set the dial to a frequency the unit will take care of maintaining it.

This genset is new to me and this is the first time load testing it. I used Diesel Kleen mixed in the fuel but I guess I have to pour more or switch to Seafoam.

Any ideas about the coolant spilling out?

 

[Light in the Dark]

Those engines don't love being bogged, and rock around a LOT during this process. It wouldn't take a small leak or defective radiator cap (or even a slightly loose drain valve) to get coolant spilled. Tighten up any connection you see before running again (hoses, drains, block petcock, radiator cap, etc).

 

[Guyfang]

I can manually compensate the frequency and increase the Hz to be as close as possible to 60. But isn't this supposed to be controlled by the governor? I assumed once you set the dial to a frequency the unit will take care of maintaining it.

This genset is new to me and this is the first time load testing it. I used Diesel Kleen mixed in the fuel but I guess I have to pour more or switch to Seafoam.

Any ideas about the coolant spilling out?

Please understand, the is no "governor" per-say on this gen set. You have a manual throttle control. When the set sences a requirement to feed more fuel to the engine, and doesn't, or take a long time coming up, it may be a Droop adjustment needed.

I agree with LITD. Load the set up, as high as you can, then let it run. Several hours. That way, the engine can get hot enough to dry up the wet stacking, and blow it out. This is not something you do while eating lunch. Get it 3-4 hours, and then try to bump the load up. The nice thing about a load bank is you can make minor load adjustments. 0.5 KW, or 1 KW, instead of large increases. Give that a try.

 

[jamawieb]

Do you have a thermo meter to take temperature? Take a temp at each exhaust port to see if you have big swings in temp. I bet one of the injectors is not putting the correct amount of fuel in the cylinder. They should all be around the same temp, but the one that is off will have a significiantly higher or lower temp

 

[Ray70]

I agree with everyone above. Start by running if for a while with seafoam, ATF or other cleaner in the fuel, and gradually stepping up the load every 20 minutes or so until you get as high as you can go without it struggling bogging and smoking.
Then remove the load, set frequency to 61.5 and reapply the max load you had before all at once. Observe the amount of droop. If it droops below 58.5 I would first try adjusting the droop ( procedure is in the manual )
Now, if you still can't get above 100% without smoke, do as Jamawieb said and check EGT with an IR thermometer.
Your electric fuel pump is fine. I also think you have either 1 or more bad injectors ( probably dirty or slightly clogged ) or you have metering pumps that aren't set correctly.
If you have a clogged injector, what happens is it overloads the other cylinders and they begin smoking. Look for either an excessively hot cylinder which would indicate an injector leaking or stuck open. Also look for an excessively cool cylinder which indicates an injector either stuck closed or adjusted too low.
Also, take a quick look at the position of the metering pumps, are all 4 of the lines feeding the pumps only about 1/8" away from the adjacent pushrod tube, or does the position vary greatly from one pump to the next?
Also, I know its a little bit of work, but when messing with injectors and metering pumps the first thing I always do is remove the top cover ( cover has to come off anyway if you need to remove injectors ) and also remove the muffler and exhaust manifold. That gives you clear sight of which cylinders are acting up and it also lets you see how much carbon is built up in each exhaust port.

 

[mesias]

I recently cleaned all injectors, one of them is new because the original had a clogged hole I couldn't clear. I also removed and cleaned two IPs that were gummed up. I might have messed up the IP install. Is it worth readjusting all pumps just in case?
I only have two steps in the device I built to load the genset, I can apply 5.4KW and 10.8KW. The smoke only appears with the max load.
I did test the temperature of both the exhaust and the intake and I don't recall having major differences. Anyhow, I'll test it again and I'll write down the readings.
I already purchased the Seafoam and I'll run the genset for a few hours on Monday. I'll run it for an hour or so on the 5.4KW load and them I'll max it out for another two hours. My major issue is the smoke and how close I have the unit to the house. The soot messed up the adjacent wall and I had to brush it off with water and detergent.

 

[jamawieb]

I recently cleaned all injectors, one of them is new because the original had a clogged hole I couldn't clear. I also removed and cleaned two IPs that were gummed up. I might have messed up the IP install. Is it worth readjusting all pumps just in case?
I only have two steps in the device I built to load the genset, I can apply 5.4KW and 10.8KW. The smoke only appears with the max load.
I did test the temperature of both the exhaust and the intake and I don't recall having major differences. Anyhow, I'll test it again and I'll write down the readings.
I already purchased the Seafoam and I'll run the genset for a few hours on Monday. I'll run it for an hour or so on the 5.4KW load and them I'll max it out for another two hours. My major issue is the smoke and how close I have the unit to the house. The soot messed up the adjacent wall and I had to brush it off with water and detergent.
[/QUOTE
Could you do a video of the startup and stopping of the unit? Didn't know you had taken the pumps out.

 

[jamawieb]

Since your last post and reevaluating the information you posted, I believe you have an injector pump problem. If you could shoot a video of the startup and shut of the unit, we should be able to tell if its the pumps. This would make sense why you cant get the hertz to stay consistent and the excessive smoke. Also in the last post you said you had soot that soaked the side of house which leads to excessive fuel being dumped into the cylinders.

 

[uniquify]

My major issue is the smoke and how close I have the unit to the house. The soot messed up the adjacent wall and I had to brush it off with water and detergent.

If the exhaust is blowing junk towards the house, you can easily redirect that with some pipe fittings. The exhaust is threaded for standard pipe (1-1/4" NPT). If it were me, I would temporarily add an elbow and a short piece of black iron pipe so it's pointing away from the house.

If you use more than 3 feet of pipe, I'd add something to help support the extra weight so it doesn't bend/break the muffler. Electrical conduit uses the same threads and is thinner and lighter.

 

[mesias]

I have it running now at 40% of capacity, no smoke with Seafoam in the fuel. L1 reads 22.4 A and L3 reads 22.8 A (the 120v fan in the load bank is connected probably to L3)
Frequency is set stable at 60Hz, no hunting.
The temperature reading of the exhaust ports changes depending where you take the reading. I aimed to the red circles in the picture below and here are the readings:
1. 229 F (Piston closest to the radiator)
2. 230 F
3. 215 F
4. 228 F



I still can't add the load from the other heat element without causing the motor to bog (not every time) or emitting a lot of greyish smoke (all the time).

Click HERE for a video of the starting and stopping of the generator. It starts right up but there is a small lag when shutting down.

I ordered some fittings and pipes to extend the exhaust. I'm planning on creating a ventury exhaust stack with a 4" PVC pipe.

I can't thank you enough for your time and feedback!

 

[Ray70]

I'm thinking you have an issue with cyl.3.
The 15* temp difference is excessive, not to mention that the heat is very much transmitted just through the steel itself, meaning that you could have a totally DEAD cylinder and the temp difference won't be night and day with a working cylinder, if you follow me?
As a quick test I would run the machine at 40% and crack the line loose on cyl 3 and see if the gen bogs or stumbles.
If you don't see much of a difference, you know that cyl.3 will need deeper investigation.
Another down and dirty quick check is to pop off the exhaust manifold, start the machine and immediate hold your finger over port#3. If the exhaust is cool compared to the others you know you have found the problematic cylinder.

 

[mesias]

After an hour of running I just checked temps again a bit above the red circle in the picture from my previous post. Here are the readings:

1. 350 F (Cyl closest to the radiator)
2. 322 F
3. 279 F
4. 294 F

The third cyl reading is still lower... I cracked the line open and no fuel at all. I never got to remove the IPs for the third and fourth cyl. I guess it's time to remove them and check them.

 

[Guyfang]

You are getting closer to the real problem.

 

[mesias]

I removed the IP for the third cylinder and i couldn't find anything wrong with it except that the internal spacer (I don't know it's name) is a bit deformed and worn out. I'm not sure what could have caused this... thoughts? Is this something that can affect the function of the IP? Any idea where i would be able to find a replacement? Here are some pics of each side and from the edge.

 

[Ray70]

Interesting, thought for sure you would have found a stuck metering pump. The pump drives off a cam follower and a little inverted cup. While the pump is out I would put something down the hole and sit it in the cup. Crank the motor by hand or with the dead crank switch and verify you have movement at the cam follower.
Basically just trying to ensure the cup or follower aren't stuck in the "UP" position.

 

[uniquify]

I removed the IP for the third cylinder and i couldn't find anything wrong with it except that the internal spacer (I don't know it's name) is a bit deformed and worn out. I'm not sure what could have caused this... thoughts? Is this something that can affect the function of the IP? Any idea where i would be able to find a replacement? Here are some pics of each side and from the edge.

View attachment 804047 View attachment 804048 View attachment 804049

Can you share a picture of that IP?

 

[mesias]

It a Delphi pump...

 

[Guyfang]

I find it hard to believe you will find a new washer anyplace. But look at Lister Peter, or who ever sells parts for the engine now. Or get a new IP. The washer looks like it was misaligned, or, installed in the wrong place? Somehow. If so, it could have prevented the IP from working.

Every-time I think about going to bed at a normal time, someone comes up with something of interest. This is one of them. This kind of thing would never come up with the military. They would simply have tossed out the old IP's and put new ones in.