MEP-002A, will Start, Run then dies....any suggestions?

[rickf]

I tend to disagree with Guyfang here. If there is fuel leaking out of that fitting, which is under pressure from the pumps, it is not going to cause a lean issue at the pump. Pressure is pushing fuel out so air is not coming is. Now, if that check valve got plugged that could do it. Did you look to see if you still had oil pressure on the gauge while this was happening? If the switch is starting to cut in and out like it would with low oil this could cause a stumbling. I am interested in this because I have a set that does this but mine is right from the start and I have bypassed ALL of the factory lines and still have the issue. So will also be learning with you on this part.

 

[Ray70]

My thoughts on the Oil pressure sensor: If the oil pressure or temp sensor are on their way out the failure mode won't be a stumble or slow-down / bog down then die condition. it will be an intermittent Shut Off condition where you will see the fuel solenoid disengage and push the IP linkage down to the off position momentarily. It will act just like you shut S1 off for a second or more.

 

[rickf]

But what if oil is low and basically the same as an oil light flickering. Fuel on, off,on,off . So it would be starting and shutting off in milliseconds

 

[Ray70]

You would still see the fuel solenoid banging up and down on the IP lever.... rapidly!
The only thing the Oil pressure switch and temp switch do is break the circuit to the Fuel solenoid, if that circuit is broken, even for a millisecond, it's only course of action is to disengage the fuel solenoid for a moment, causing it to push down against the lever of the IP.
Normally the solenoid is all the way up and well away from the linkage.
If it stays up there and doesn't move as the engine begins to stumble and die, then neither the oil nor temp switches would be the cause.

 

[1FAST4]

Yes it could. Also, item 16 is a check valve. Did you soak it in what ever wonder juice you used to clean the fuel system. Its also a great place for trash to gather. Then the gen set stops, just like yours. I would take the check valve out to LOOK/CLEAN/CHECK and at the same time, get a glass jar and hold it at the end of the fuel line. Turn on the pumps and check to see if there is any trash coming out.

I had already removed the Check Valve; soaked, cleaned and checked the flow prior to the startup yesterday, all seemed good. I will check it again when I remove Items 10-12 to tighten everything up to stop the leak.

 

[1FAST4]

Did you look to see if you still had oil pressure on the gauge while this was happening?

Here is a link to the video of the initial startup yesterday. Looking back at the video I can now see the leak may be more then I described in my post; as I pan around to the area of the Oil Pressure Gauge you can see Oil pressure was around 45 PSI but maybe more importantly the fuel leak had/was "spraying" fuel. The Gen Set ran for about 15 mins after the video ends. I did not see or look at the Oil Pressure Gauge as the Get Set started to stumble and then die.

Video of Startup

 

[Guyfang]

I tend to disagree with Guyfang here. If there is fuel leaking out of that fitting, which is under pressure from the pumps, it is not going to cause a lean issue at the pump. Pressure is pushing fuel out so air is not coming is. (But, the fuel pressure to the IP IS reduced when you have a leak) Now, if that check valve got plugged that could do it. Did you look to see if you still had oil pressure on the gauge while this was happening? If the switch is starting to cut in and out like it would with low oil this could cause a stumbling. When I am interested in this because I have a set that does this but mine is right from the start and I have bypassed ALL of the factory lines and still have the issue. So will also be learning with you on this part.

 

[1FAST4]

Leak fixed. After removing Items 10-12 in the below diagram, I inspected and cleaned them once again; check valve did not have any debris in or around it and the internal valve moved freely and was not "sticky". I then reinstalled everything to test pressure of the fuel system; I first tested at the upstream hose fitting coming out of the last fuel filter; the pressure held at 10+ PSI for 5 mins with no leaks downstream. I then tested at the 90° fitting (#10 of the diagram) upstream from the Check Valve; the pressure held at 10+ PSI for 5 mins with no leaks downstream. I then reconnected everything turned S1 to Prime for 5+ minutes and no leaks...there was a small amount for fuel going into the day tank via the IP return hose as it should be.


I then tried to start it. It fired up, came up to speed and ran for about 2 mins then the same issue; RPM's would slowly decrease to where it would start knocking then it would recover, back up to speed, then slowly decrease RPM, knock with gray/white smoke...Just a FYI, I'm not letting it continually run this way or till it dies for fear of damaging any of the electronics, I just shut it off.

I was very comfortable and confident working on the Fuel System but now I am so frustrated because I don't know enough about this machine to properly diagnoses what's going on with it and feel I don't always have the best ability to describe it to you guys in a way that you can help...Ah, it's so frustrating....

Below are a few Videos of what it's doing and what the Governor linkage is doing...if it helps?
Vid-A
Vid-B
Vid-C



Thanks All!!!!

 

[2Pbfeet]

Leak fixed. After removing Items 10-12 in the below diagram, I inspected and cleaned them once again; check valve did not have any debris in or around it and the internal valve moved freely and was not "sticky". I then reinstalled everything to test pressure of the fuel system; I first tested at the upstream hose fitting coming out of the last fuel filter; the pressure held at 10+ PSI for 5 mins with no leaks downstream. I then tested at the 90° fitting (#10 of the diagram) upstream from the Check Valve; the pressure held at 10+ PSI for 5 mins with no leaks downstream. I then reconnected everything turned S1 to Prime for 5+ minutes and no leaks...there was a small amount for fuel going into the day tank via the IP return hose as it should be.
View attachment 939097

I then tried to start it. It fired up, came up to speed and ran for about 2 mins then the same issue; RPM's would slowly decrease to where it would start knocking then it would recover, back up to speed, then slowly decrease RPM, knock with gray/white smoke...Just a FYI, I'm not letting it continually run this way or till it dies for fear of damaging any of the electronics, I just shut it off.

I was very comfortable and confident working on the Fuel System but now I am so frustrated because I don't know enough about this machine to properly diagnoses what's going on with it and feel I don't always have the best ability to describe it to you guys in a way that you can help...Ah, it's so frustrating....

Below are a few Videos of what it's doing and what the Governor linkage is doing...if it helps?
Vid-A
Vid-B
Vid-C

View attachment 939104 View attachment 939103 View attachment 939102

Thanks All!!!!

Listening to the videos and watching the governor move, it doesn't seem that the position correlates well with the engine speed.

 

[1FAST4]

Listening to the videos and watching the governor move, it doesn't seem that the position correlates well with the engine speed.

Could you please explain more...I'm not understanding what you mean?

 

[Scoobyshep]

Beginning of vid c. The linkage moves up then the engine stalls. Up is more throttle, it's odd that it moves up before is sounds like an stall.

 

[Chainbreaker]

Beginning of vid c. The linkage moves up then the engine stalls. Up is more throttle, it's odd that it moves up before is sounds like an stall.

Hmmm, you just triggered a thought. I'll throw this out there:

We know with his latest videos that the fuel pumps are flowing good fuel now. In post #37 in Video #6 it shows it dying with a lot of white smoke. Typically, white smoke is unburned fuel like on initial startup before it comes up to operating temps.

So, what if one of the 2 cylinders is getting too much, or perhaps too little, fuel as in a sticking injector or misadjusted injector... pop off pressure? Since the MEP-002's are only two-cylinder engines having just one cylinder firing will cause it to slow down & run rough on just one cylinder. With one cylinder falling off & dying the other cylinder is getting flooded with too much fuel (as the governor is responding to throttle setting & wanting to increase falling RPM's) that might end up cooling cylinders with unburned fuel and exit exhaust as white smoke.

Just a theory...

 

[Ray70]

Well, at this point I'd say the fuel delivery system should be all set. The smoke thing has bothered me from the beginning and it is now seeming more and more like an injection pump or injector issue as CB mentioned.
A skipped plunger guide in the pump would have a similar effect, but typically makes it a little hard to start and the valve cover will get hot very fast.
Either way I think its time to investigate the injectors and then the IP plunger guide.

 

[rickf]

Thank you very much for that last video! That is exactly what mine does. So I will be watching this to see where it heads. On mine I completely bypassed the whole fuel system and ran from a fuel can through a small inline filter into the p[ump to eliminate any and all restrictions and I got this same result. Ray and I have talked about that one in the past. I was going t work on it over the winter but this winter has been substantially colder than the last few so no workee out in this on genset.

 

[2Pbfeet]

Beginning of vid c. The linkage moves up then the engine stalls. Up is more throttle, it's odd that it moves up before is sounds like an stall.

@1FAST4 What @Scoobyshep wrote is what I noticed as well. You didn't (I think) have a variable load, and yet the governor linkage is moving all over the place trying to keep the engine speed constant. Plus, there is a perhaps subtle shift in the engine sound at the same rpm, as if something flakes out and the engines is able to compensate, or compensate for a bit before stalling.

At this point, I think that you probably have the fuel to the injection pump sorted out, (did you blow out the intake port on the pump with compressed air and carburetor cleaner?), which leaves the white smoke from unburned diesel. That might be something wrong with the injection pump, or the injectors, or something that might cause an intermittent lack of compression, or a lack of compression as the engine warms up. I would start with the injectors, and then I would double check the valve clearance and function as "easy stuff", then the flow through the IP, and see where you are at that point. Personally, I try not to pull injection pumps until I am reasonably certain that the issue is in the pump. I'm not saying it is the right thing to do, just that I recognize that pulling a pump can often be a bit of a loose ball (for me) getting it back on the engine correctly.

My issue with finding "gunk" in the fuel system is always wondering how far the gunk went. A certain former elected official in Boston was once quoted saying "the trouble with getting an envelope with $450 in it is you don't know whether the guy handing it to you took out $50 or $550". Did I find all of the gunk, or just some of it?

All the best,

2Pbfeet

 

[Scoobyshep]

If it were me, I would check clearences, then pull injectors for testing (while they are out compression test). unless i absolutely need to, i tend to leave the IP in place as they are a pita and the timing procedure is annoying

 

[2Pbfeet]

@1FAST4 One other item: I wouldn't trust your Hz meter, without verification. It seemed to be jumping around far more than the engine rpms.

All the best,

2Pbfeet

 

[1FAST4]

Yesterday when I got home, I read through all your recent posts and also reread through this entire thread to see if I missed any troubleshooting steps, you all have suggested. The only thing I had not done was clean and blow out the input port on the IP as asked by "2Pbfeet". So, I went out and did that...I first sprayed the whole area and IP with Carb Cleaner including the throttle and governor linkage then blew the area out with compressed air. I removed the fuel hose that connects just upstream of the check valve and runs to the IP, also remove the 90° fitting that connects into the IP inlet (this a bit tough due to the tight space and angle of the fitting so I made a tool to safely get it out.) and sprayed them out with Carb Cleaner and air. I sprayed the inlet of the IP with a lot of Carb Cleaner than blew it out with air multiple time; I blew it out until no residual Carb Cleaner came out. Then reconnected everything.

I added a full can of Seafoam into the 2 or so gallons of fresh Diesel in the day tank then turned S1 to Prime. I left it on Prime for about 5 mins to push the Seafoam/fuel through the system with the goal of getting the Seafoam into the IP and past the Injectors. I then started it. It ran rough with a faint knocking sound for about 2 to 2½ minutes before it died with a gray/white puff of smoke. While it was running, I moved the Throttle linkage up and down and the engine responded but it just never smoothed out before it died.

Man, this thing is kicking my butt!!! I just can't understand why this Set, that ran perfectly since I've had it (since 2012) could sit quiet for 6 months and then boom! not run as it always did. I was for sure thinking it was a "simple" fuel issue, i.e. old fuel, a bad pump, a clogged fuel line or check valve and/or something similar and what I would consider an easy fix.

What is the consensus on the next step(s) you guys think I should take?

 

[1FAST4]

@1FAST4 One other item: I wouldn't trust your Hz meter, without verification. It seemed to be jumping around far more than the engine rpms.

All the best,

2Pbfeet

I have used a Kill-A-Watt, plugged into the 120v convenience outlet since day one just for that reason.

 

[Ray70]

I know several others mentioned they would shy away from the IP until 100% sure, but me personally I have seen so many issues with the garbage fuel these days causing IP problems after sitting for a few months, I would just bite the bullet and take it off and go through it, paying close attention to the plunger guide. There is no "timing" procedure needed in your case. Just set the engine to the correct spot as mentioned in the TM ( #1 cyl compression stroke with "PC" mark aligned with the pointer ) Take it out per the instructions and disassemble and inspect. If you have any problem or questions I can help you, I've rebuilt dozens of them in the past.
One thing to note: The IP rebuild instructions in the generator's TM are incorrect, they are for the PSU injection pump, not the Ambac M-50 that you have, but I have the instructions and diagrams for the M-50 if you need them. I assume the Ambac manuals etc. are also available in the TM section, but not positive.