MEP-802a fuel rail

[jamawieb]

I'm in the process of working on 802a which had the injector pumps removed. I installed new pumps but can not get them to pump. I believe my problem is with the fuel rail. I can take the pumps out and feel the fuel rail and move it front to back with my index finger. But if I keep my index finger on the fuel rail and I try to move the fuel shut off lever to the On position (pulled back towards the generator head), I can't get the fuel rail to move back. If there is no pressure on the fuel rail (from my finger), the fuel shut off lever will move it fine but with just alittle pressure it wont move. I should mention, that I can move the fuel rail back (to the on position) with my finger and then move the fuel shut off lever to the off position and it will pull the fuel rail forward without any problem. So I'm thinking that the fuel rail can't move back to place the pumps in the on position. The TM doesn't really show what moves the fuel rail back and forth so I'm hoping someone can guide me in the right direction. I hope I don't have to take the front of the motor apart to get to the governor linkage.

 

[Guyfang]

There is a previous thread that might help you out. I am trying to remember who started it. Several people in the forum have posted good information on the fuel rail and repairs. If you look in the manuals section, I posted manuals needed to repair the 802 and 803 sets. The last document in the list is the adjustment for your fuel rail. Take a gander at that, you will need to do it when you are done.

 

[jamawieb]

Hey Guyfang, yes I'm an avid member and won't post anything without research. One thread I read was MEP-802a shorted, now running rough and then Pclausen of how he is rebuilding 3 mep-802a's. I have saved and read over your manual from the engine manufacturer on the fuel rail and fuel pump replacement from a previous post. But I can't figure out what moves the fuel rail. I'm trying to figure out how it works without taking the front of the motor apart. I'm really glad you responded because I was hoping you could help with all your experience.

 

[Guyfang]

Well, its almost 23:00 here and this old soldier has to rest a bit. I will give it some thought while watching the news and we will see what the new day brings. Will the engine turn over by hand?

 

[jamawieb]

Thank you so much. Yes everything moves freely, when I take the injector line off the pump, I don't get any spray and it's getting fuel from the fuel pump. If I put pump #1 in and move the fuel rail with my index finger through #2 injector port and move the fuel rail back, I can get solider 2 to hit the start switch, I can get fuel out injector pump 1. So I'm almost 100percent sure its the fuel rail.

 

[fastbackperry]

I'm having virtually the same problem. Bought generator that was suppose to run but it wouldn't start. Turned over but no go. Eventually it ran and I turned it off and on numerous times. Personally thought it should start quicker. Anyway then no start. Checked fuel at IP which are both very clean and move fine. There was not squirting going on from there. Pulled the 1st pump and put my finger in hole like Jamawieb stated. Obviously the pin on the injector goes in slot of fuel rail. Strange thing was that I could actuate the fuel shut off lever and feel the rail move back and forth but there was a definite slip in the linkage like a gear tooth was being jumped. Thought it was normal so let it take up the slack then inserted IP. It primed and when the engine turned over it squirted like it should. Second IP didn't so went through process again. Both squirting so pulled top cover and air cleaner housing so I could crack injectors. Got them squirting soon so tightened them. Tried to start but really never caught. Cracked injectors and no squirt. I did see the last page of one TM that noted the fuel rail hang up but something seems more wrong than that. I'm baffled to so came in to study the TM. Already pulled radiator in preparation of pulling engine front cover off but hopefully I don't need to. Hopefully comparing notes will get us both fixed. Perhaps we could connect over the phone as well. Thanks. Perry

 

[fastbackperry]

One other thing. I have a little bit of crankcase pressure as it turns over and running. That would suggest damage to cylinder walls thus blow-bye I'm thinking. Engine seems to be in good shape with no water issues. I don' t see a crankcase breather of any kind which is really strange. Anyway, pressure doesn't blow dip stick out but close and when I pull it out it blows a little oil out. I don't like that. Thoughts? Thank you

 

[Guyfang]

If you have pressure on the crankcase, indeed you probably have a ring problem. There should be a slight vacuum on the crankcase if I remember correctly. That's why there is no crankcase vent.

The fuel rail is, and has been a problem the entire life cycle of the MEP-802 and 803 existence. Both you need to think hard about pulling the rail and seeing if it is bent. This was a very common problem. Often someone would pull BOTH pumps at the same time. Not good. You should only pull one out, replace it, then the second one. It could be that someone at an earlier time, pulled both, then bent the rail putting them back in.

Something else. Its small and no big thing, but when a generator mech to talks about front and back of the set, The front is where the radiator is, the back is the control panel. Doesn't matter what kind of set. Always this way, then you do not have to think about it.

In post #3, the question asked is how the rail moves. The rail can only move to full fuel when the fuel solenoid is activated. It pulls back when the engine starts. The only way it springs back to no fuel is by the spring tension, from the return spring, Figure 9, item 41. So, Jamawieb, You might need to look at the linkage and in the return spring area. Does it appear that someone has taken it off? Is the paint disturbed? If everything is in order outside the engine, then it can only be inside the engine block. It really sounds like a bent rail to me. There are about a kazillion parts inside the block that have to be exactly in the right place to function. Opening it up is the only way to check it out.

 

[fastbackperry]

Thank you. How is vacuum achieved on the crankcase? Where's the best place to buy gaskets for these engines?

 

[Guyfang]

Now you got me. Its a closed system, so I think the pumping of oil from the sealed crankcase would create a vacuum. I remember that I used a water manometer to check to see if I had a pressure or vacuum. Cant remember how many inches displacement told me to get a new engine. Darn, I forget soooooooooooooooooo much now days. Will try to remember.

In serious cases, have seen the dipstick shoot out of the tube. As you are supposed to be able to check oil while running the set, I learned real fast to be VERY careful when I pulled a dipstick. For a while, the army had a shortage of dipsticks. So many had shot out of the tubes, gotten lost in the set, or someone was too lazy to look hard for it. THEN, to get a dipstick, everyone began to steal them. No kidding.

Gaskets? How hard have you looked in the internet? Lister Peter if nothing else. We made some, ordered the gasket material and cut some out. Its not hard. TM covers were a fine substitute for proper gasket material. But that's a field fix in my eyes. Take the NSN and part number for the individual gasket, and kits, run them through the Ebay and other such places.

 

[fastbackperry]

Thank you. No stress on remembering the crankcase vacuum or pressure. I'm thinking it will clear up once running for a longer time. I'm tempted to pull the pipe plug on front of engine and plumb it for some sort of vent but not a priority now. That fuel is the issue I'm certain of. What does NSN mean? I'll go look around for that gasket. Thank you

 

[Guyfang]

NSN is Army talk for National Stock Number. In the army, you dont order parts by part number, you order by NSN.

 

[Guyfang]

The engine is made to run with a slight vacuum. Do you have manuals? Parts and maintenance procedures? What condition is your set in? If its seen better days, I often filled the oild sump up with dextron and ran it for two hours, no load. Drain and flush twice with cheap oil, change filters also. Sometimes the rings are a bit "sticky". Often had less blowby after doing that. Might help.

 

[fastbackperry]

Thank you Guyfang. The generator set is in good shape. 900 hours. I pulled front cover off today and all is good inside. That fuel shut off rail I believe is the issue as if it can move to far in the direction of shutting off the IP pin/levers will come out of the rail and not go back in when the rail moves in the other direction. My on off lever had been broken so may have allowed the above to happen. All is good inside now. Just waiting on a new lever/shaft either from William at Delk's or a nice fella in Oregon that has a parts motor. As far as the crankcase pressure I believe I'm good. Hopefully with some running there will be less. Talked to my diesel mechanic and he said that is common especially with non vented cases. A opinion question for you though. I've had several MEP-003's and a couple 002a's. I bought them off GL to resell. I kept one of the newest and put a ASK kit on it. Made one for another as I was in sheetmetal fabrication but bought a 003a with the kit which I switched over to a 20 hour 003 I keep in the garage in case things get crazy here in the Puget Sound area after a earthquake or national disaster/problem. My question is are these 802's and 803's any better then the 002 or 003 units? Yes quieter by a little since they come with a enclosure but an 002-003 with enclosure isn't that much louder. Another guy said they have more electronics that are prone to issues and the Lister/Petter engines are great but do have slight issues by the sounds of it. Anyway, I'm keeping my 003 no matter what and this 802 will go down the road when back together. Just curious what your thoughts are since you seem to have much more exposure/knowledge about these 5 and 10 kw gen sets. Thank you.

 

[jamawieb]

fastbackperry it sounds like I have your problem. Since you have taken the front of the motor apart and seen the problem. Do you think there is a way to fix the problem without taken the front of the motor apart?

 

[fastbackperry]

OK. I'll do the best I can here to describe for you what I've found. I really appreciate it when others have taken time to help and explain to me things I'm stumped on so I'm going to try to do the same here but it may be a little long winded.

What I find on the fuel shut off rail is that it moves forward and backward freely with or without IP's in place. There is a spring at the front of engine behind cover that pulls the fuel rail to on position towards the back of the engine. When using the fuel shut off lever, solenoid bracket detached, you can turn the lever CCW and feel a slip happen like it skipped a tooth if it was geared. It is not geared as you know but the assembly on the shut off/on lever on the inside of the engine has two parts one of which is spring loaded. This little part, call it a finger, slips past the fuel rail contact surface giving you the feel that something just slipped. Just behind it though is the main contact part of the fuel shut off/on lever that will push the rail forward. When you let off, the rail returns because of spring, and that little finger helps in pushing rail backwards or on again. You've seen the addendum that talks about fuel shut off bolt adjustment I think. It is talking about how the fuel shut off/on lever is allowed to move CCW to far, moving the rail forward to far, and it catches/binds on something internally leading to a no start. That's why the instructions to lengthen the bolt so that the stop position is less rotation CCW. It is a challenge to make sure the IP on/off pin drops into the rail grooves. As you know you turn the on/off lever CCW and you can feel the rack move forward exposing these rail grooves on the lower left forward side of the IP holes. This can be observed with a mirror as well. I found that moving the IP lever backward a little off of full shut off helps in getting the IP and on/off pin to drop into rail grooves. You'll know it's in the right place as when moving the fuel on/off lever you will see the IP move CW and CCW. If it doesn't then the pin is not in the groove and you'll need to lift it up slightly and try again. Once all injectors are in place do not turn on/off lever to far CCW. It may be helpful to rotate the engine by hand when dropping IP in as the cam lobe may be up and not allowing the IP to drop in as low as needed. Tighten IP hold downs with IP's kinda centered or where you noted they were before moving them. At this point I'd try starting the engine without the fuel start stop solenoid linkage attached. Have a big rag handy to muffle the intake tub or your hand will do to kill the engine if needed. At this point hopefully it will start right up. I'd then slowly turn the start stop lever CCW until the engine stopped noting this position and adjusting the upper bolt stop out towards contact surface on start stop lever. After that Perhaps screw bolt stop in a turn to ensure stopping engine. Hook up linkage and you are golden hopefully. I wonder if somehow the IP pins can come out of the rail grooves if the rail is allowed to travel to far forward or backward as I thought for sure I'd installed both injectors correctly getting them to squirt nicely, attached lines, cracked injectors getting fuel squirting there, then no luck on getting to fire up. Strange. Currently I know that both injectors are where they are suppose to be but am waiting on the start/stop lever shaft assembly as something had bent the aluminum part of this assembly inward where it was barely touching the stop adjustment bolt. I knew I was gambling trying to bend it back out and sure enough it broke. Cast aluminum. Anyway, waiting on that part to install before I put cover back on and adjust my adjustment bolt, then try to start. Seems pretty simple but has been challenging to say the least. Has great compression and with fuel going to the injectors it should run. It did run before for a couple hours with multiple shut down and start ups then it failed to start. PM me to talk this through if you like as I don't want to post my number here. We'll then be able to help eachother out. Good luck. Perry

 

[Guyfang]

My question is are these 802's and 803's any better then the 002 or 003 units? Yes quieter by a little since they come with a enclosure but an 002-003 with enclosure isn't that much louder. Another guy said they have more electronics that are prone to issues and the Lister/Petter engines are great but do have slight issues by the sounds of it. Anyway, I'm keeping my 003 no matter what and this 802 will go down the road when back together. Just curious what your thoughts are since you seem to have much more exposure/knowledge about these 5 and 10 kw gen sets.

Here's my take on this question. The 002 and 003 engines are without a doubt, a better engine. Hands down. This engine will run without fail, for ever. The only real problem I ever saw, that is what I would call a show stopper, was the injector pump. I have only changed 4-5 in an almost 30 years power generation repair. They are easy to change. Easy to time. Last forever. If one reads the book. I also feel that the 002 and 003 are by and large, electrically, a better built, longer lasting machine. BUT, the 802 and 803 are easier to troubleshoot, easier to repair and parts are not going to become an issue as with the 002 and 003. Some of these sets are 40 years old. Parts are harder to come by, I think. The only reason I would get rid of one of the 002/003 sets is because of parts. So long as you have an adequate supply of parts, I would never give one up. But that's just one mans opinion. I am an old dinosaur. Some of the other members here have developed new components/parts to replace the old ones. And they seem to work as good, or better. There are some smart cats here in the forum. No shortage of ideas. Perhaps that will make up for the supply base running out one day. I destroyed my hearing with power generation, rock concerts and turbine engines. The TQG's are much easier on the ears. But, I can remember running a MEP-003 for two monthes, turning it off, servicing it and running it another two months. A TQG would have a hard time matching that.

 

[DieselAddict]

I reluctantly sold my cream-puff 003 and replaced it with a fresh 803.

I'm sure the neighbors will appreciate the switch more than the sadness I felt to not seeing the 003 on the trailer.

 

[jamawieb]

Here's my take on this question. The 002 and 003 engines are without a doubt, a better engine. Hands down. This engine will run without fail, for ever. The only real problem I ever saw, that is what I would call a show stopper, was the injector pump. I have only changed 4-5 in an almost 30 years power generation repair. They are easy to change. Easy to time. Last forever. If one reads the book. I also feel that the 002 and 003 are by and large, electrically, a better built, longer lasting machine. BUT, the 802 and 803 are easier to troubleshoot, easier to repair and parts are not going to become an issue as with the 002 and 003. Some of these sets are 40 years old. Parts are harder to come by, I think. The only reason I would get rid of one of the 002/003 sets is because of parts. So long as you have an adequate supply of parts, I would never give one up. But that's just one mans opinion. I am an old dinosaur. Some of the other members here have developed new components/parts to replace the old ones. And they seem to work as good, or better. There are some smart cats here in the forum. No shortage of ideas. Perhaps that will make up for the supply base running out one day. I destroyed my hearing with power generation, rock concerts and turbine engines. The TQG's are much easier on the ears. But, I can remember running a MEP-003 for two monthes, turning it off, servicing it and running it another two months. A TQG would have a hard time matching that.

I 100% agree.The 800 series are awesome but for reliability I would chose a 000 series. The only thing I wish the 002 or 003 had was an overvoltage fault, because when the regulators fail it sends 140+ into the house.

 

[jamawieb]

OK. I'll do the best I can here to describe for you what I've found. I really appreciate it when others have taken time to help and explain to me things I'm stumped on so I'm going to try to do the same here but it may be a little long winded.

What I find on the fuel shut off rail is that it moves forward and backward freely with or without IP's in place. There is a spring at the front of engine behind cover that pulls the fuel rail to on position towards the back of the engine. When using the fuel shut off lever, solenoid bracket detached, you can turn the lever CCW and feel a slip happen like it skipped a tooth if it was geared. It is not geared as you know but the assembly on the shut off/on lever on the inside of the engine has two parts one of which is spring loaded. This little part, call it a finger, slips past the fuel rail contact surface giving you the feel that something just slipped. Just behind it though is the main contact part of the fuel shut off/on lever that will push the rail forward. When you let off, the rail returns because of spring, and that little finger helps in pushing rail backwards or on again. You've seen the addendum that talks about fuel shut off bolt adjustment I think. It is talking about how the fuel shut off/on lever is allowed to move CCW to far, moving the rail forward to far, and it catches/binds on something internally leading to a no start. That's why the instructions to lengthen the bolt so that the stop position is less rotation CCW. It is a challenge to make sure the IP on/off pin drops into the rail grooves. As you know you turn the on/off lever CCW and you can feel the rack move forward exposing these rail grooves on the lower left forward side of the IP holes. This can be observed with a mirror as well. I found that moving the IP lever backward a little off of full shut off helps in getting the IP and on/off pin to drop into rail grooves. You'll know it's in the right place as when moving the fuel on/off lever you will see the IP move CW and CCW. If it doesn't then the pin is not in the groove and you'll need to lift it up slightly and try again. Once all injectors are in place do not turn on/off lever to far CCW. It may be helpful to rotate the engine by hand when dropping IP in as the cam lobe may be up and not allowing the IP to drop in as low as needed. Tighten IP hold downs with IP's kinda centered or where you noted they were before moving them. At this point I'd try starting the engine without the fuel start stop solenoid linkage attached. Have a big rag handy to muffle the intake tub or your hand will do to kill the engine if needed. At this point hopefully it will start right up. I'd then slowly turn the start stop lever CCW until the engine stopped noting this position and adjusting the upper bolt stop out towards contact surface on start stop lever. After that Perhaps screw bolt stop in a turn to ensure stopping engine. Hook up linkage and you are golden hopefully. I wonder if somehow the IP pins can come out of the rail grooves if the rail is allowed to travel to far forward or backward as I thought for sure I'd installed both injectors correctly getting them to squirt nicely, attached lines, cracked injectors getting fuel squirting there, then no luck on getting to fire up. Strange. Currently I know that both injectors are where they are suppose to be but am waiting on the start/stop lever shaft assembly as something had bent the aluminum part of this assembly inward where it was barely touching the stop adjustment bolt. I knew I was gambling trying to bend it back out and sure enough it broke. Cast aluminum. Anyway, waiting on that part to install before I put cover back on and adjust my adjustment bolt, then try to start. Seems pretty simple but has been challenging to say the least. Has great compression and with fuel going to the injectors it should run. It did run before for a couple hours with multiple shut down and start ups then it failed to start. PM me to talk this through if you like as I don't want to post my number here. We'll then be able to help eachother out. Good luck. Perry

Thank you so much Perry for the write up. I'm going to try to realign the fuel rail without taking the front apart to save time but I will let everyone know how it goes.