MEP-002A, 003A Fuel Pump Failures

[RichardR]

Hello all you MEP-002, 003 experts,

I have experienced several fuel pump failures on MEP-003A generators, and I wonder if anyone else has had a similar experience. The fuel pumps I am talking about are the low pressure 24 Volt oscillating piston pumps, located below the control box, that suck fuel out of the tank and deliver it to the filters at about 5 to 10 psi. I notice that there are at least two slightly different versions of this pump, one with a small cigar-shaped EMI filter in the power line and the other with a cube-shaped EMI filter. They are shown in the attached pictures. The one with the cube EMI filter is stamped Facet 480517E, and I don't find a similar stamping on the other kind with the cigar-shaped EMI filter although it may just be covered with CARC. THE TM calls out part number 480517.

I have had 3 of the cube-shaped EMI filters develop internal hard shorts to ground. And one of the 480517E pumps (before removal of the soon-to-fail cube EMI filter) failed in its internal electronics (wouldn't turn off the magnet to let the plunger return to its non-energized position). All of these pumps had been cleaned and were operating normally just before sudden failure. And all failures happened within about the first hour of operation (after perhaps years of non-use).

I think the "E" pumps with the cube EMI filter are the latest version of the pump, replacing the version with the cigar-shaped EMI filter. Seems like most of the "fresh" resets have one or more of the "E" pumps, which look newer than any pump with the cigar-shaped EMI filter.

Has anyone else had problems with the "E" pumps and the cube EMI filter? I think I would rather stay with the older version (cigar EMI filter) because I have never (yet) had a problem with them. Of course, all these pumps get varnished up and stuck if not used often enough, but I don't think that has caused any of the problems I have experienced.

Thanks for reading this long-winded post, and for any advice/preference feedback on what's going on with my pumps.

Richard

 

[Speddmon]

I think I would start looking for a DC problem on your generator if I were you. A LOT of people have these generators, and the biggest problem reported by most people is plugged inlet screens and just frozen up from sitting on a GL lot for a year with old nasty diesel in them.

I think you may have a problem with your DC wiring somewhere on the set causing surges to be damaging pumps like you report.

 

[storeman]

"Speddmon, I think I would start looking for a DC problem on your generator if I were you. A LOT of people have these generators, and the biggest problem reported by most people is plugged inlet screens and just frozen up from sitting on a GL lot for a year with old nasty diesel in them."

I agree. These pumps are hard to kill. I think you have a DC problem, aside from the pumps/filters.
Jerry

 

[RichardR]

Speddmon,

Thanks for the quick response! You may very well have nailed the problem in your assessment. I thought about spikes on the DC causing exactly what is happening, but dismissed it as unlikely on such a relatively simple machine. The DC generator on an 003A puts out only about 6 amps so that didn't seem like a good suspect. I was thinking more about the starter and its solenoid causing spikes, but the failures occurred when the genny was running. HOWEVER, the particular machine where I believe most (perhaps all) of the failures happened had a very strange problem involving the voltage regulator card and a stray ground from a too-long pop rivet touching the back of the card. That caused the starter cutout to not work correctly, and I tracked down and fixed that problem only with the aid of very strong language and lots of head scratching. Point is, it was a problem in the DC circuitry just as you suggest. Maybe that was it!!! And now it is fixed, but too late to save my fuel pumps.

I should report on that stray-grounding-by-pop-rivet problem in more detail in the hope that it could save some other poor soul all the trouble I went through, no matter how unlikely it is that it will ever happen to someone else. And, indeed, I will do that as soon as I get organized. I can assure you that that particular problem is not to be found in the troubleshooting flow charts in the TMs!

Nevertheless, if nobody else has experienced fuel pump failures like has happened to me, I certainly believe that the problem is peculiar to my machine and that you have quickly and correctly narrowed the scope of the problem to spikes on the DC rather than to an inherent weakness in the fuel pumps themselves. Those darn pumps are too expensive to keep replacing without knowing exactly what I am up against.

Thanks for your good advice,
Richard

 

[RichardR]

And Storeman, thanks for your advice and concurrence, too. I'm now convinced that it is spikes on the DC, no matter how unlikely that seemed to me at first. I was trying to blame it on the pump, but that isn't where I should have looked.

Regards,
Richard

 

[ETN550]

Myself and one other member recently each had a failure of the round style Facet pump where it failed as short to ground and tripped the breaker. These were brand new pumps with little use. Both were on 016E. I thought at the time that there may be a manufacturing problem with some of the newer ones. The old ones seem very very reliable. Never seen one bad other than the new one. Probably set up over 20 units in the last 6 months. Like stated above, gumming up and clogged screens and sticky plungers are common. Quick teardown and cleaning is SOP.

Others have said the square ones are not as good. The newer 5kw 802A and 10kw 803A use square ones.

The MEP-016D sends 45 - 55 volts dc to the same pump. Rectified flywheel A/C output without regulation. I don't like it but that's how they are made.

 

[coyote62ny]

i would also check the voltage across the batteries when running it should be 27 to 28.5 volts dc. i had a dc voltage regulator go bad and the voltage across the batteries was up to 32 volts dc.

 

[RichardR]

ETN550,

The fuel pump that failed me was a round Facet 480517E. It failed by refusing to de-energize its internal solenoid and letting the pump plunger return for another stroke. I believe all the round Facet pumps used in these gennys have external EMI filters in the DC power line. The old model pump (Facet number unknown to me) uses a tubular cigar-shaped EMI filter, and the new model (Facet 480517E) uses a cube shaped EMI filter.

The pump that failed didn't draw enough current to pop the breaker, but the 3 cube shaped EMI filters that developed hard shorts to ground certainly did.

I believe that the pump in the MEP-016E must be the same type as in the MEP-002, 003. The picture below is of an older MEP-016B and its fuel pump, but it's probably the same as the 002 and 003. I'm guessing that later builds of the MEP-016E have the newer Facet 480517E with the cube-shaped EMI filter. It may be that the newer cube-shaped EMI filters and perhaps the pumps themselves, are more susceptible to failure from high voltage on the DC line. I'm not completely convinced yet, but based on everyone's experience supporting the reliability of the old pumps with the cigar-shaped EMI filter, I think I'll try to stay with the old pump. To be completely fair to the new pump and its EMI filter, I acknowledge that my MEP-003A had a problem that was probably causing spikes on the DC line.

I have heard the same reports as you, saying that the new square-shaped pumps are less reliable. But I have limited experience on only two MEP-802A with that style pump and haven't had any problems yet.

Coyote62ny,
I'm pretty sure that the battery charger in my -003A is OK. Haven't seen any indication of high battery voltage, and I usually pay attention to the meter.

Regards,
Richard

 

[coyote62ny]

when mine messed up with high voltage the dc battery condition meter on the panel went up into the red. i later found out i had a bad dc voltage reg. the over voltage was just a thought.

 

[NJ_Toolnut]

Richard, where did you source the new Facet pump with the cube-shaped EMI unit?

Stan

 

[RichardR]

Stan,

The Facet 480517E fuel pumps, the ones with the cube-shaped EMI filters, came directly from GL on a pair of MEP-003As. So they must have been installed by the military or civilian contract rebuilder during a reset. They looked newer than some of the old style pumps on the same machines.

Facet also sells the 480517E direct to the public if you order one. Many marine (boat) shops sell them. I believe they are just a newer model of the pumps on all MEP-002A, 003A. The older ones had a cigar-shaped EMI filter and something different about the contacts that energize the solenoid in the pumps. The new ones (the "E" model) are supposed to have a solid state switch that energizes the solenoid.

My experience is that the new model isn't nearly as good as the old one. YMMV. If you have the old model, you should be happy. If you have the new model, be careful about keeping the batteries firmly connected when running, and don't connect/disconnect anything on the 24 volt buss while running.

Regards,
Richard

 

[NJ_Toolnut]

Thanks, Richard!

I saw the image of the box and the pump with no CARC on it you had attached to your post, and I guess I assumed you had purchased one aftermarket...I scanned the thread instead of reading carefully. Good info that they can be purchased directly from Facet, but by the sounds of things, purchasing a used old style model from storeman (if available) might be less risky (and expensive). The three on my 003a are old style (cigar-shaped EMI unit).

I ran my 003a for two hours last night for the first time in a couple of months, and it performed perfectly. I've been trying to run it once a month, but I missed May due to too many simultaneous other projects.

Stan

 

[RichardR]

Stan,

That picture wasn't of one of my failed pumps; just intended to show the difference between old and new styles. I plagiarized it from an eBay seller who had a single new pump for sale. Sold for $100 + shipping, but not to me. Still, a bargain I suppose, if someone HAD to have a new one. I'm sure Facet wants much more than that for one, and the boat shops have them priced around $200.

Glad to hear that your MEP-003A is running well. It will last a long time. You really put a lot of work into recovering from that unfortunate situation with the "extra" nut in the gear case.

Best regards,
Richard

 

[Isaac-1]

One note I see someone mentioned these pumps being used on the MEP-016d the two I picked up from GL this week both have Walbro FR series fuel pumps one had the kit installed by a contractor using custom hosesand wiring the other appears to be a field job using barb connectors. Both conversions dated 2003

 

[Isaac-1]

Well I tried to run my new MEP-002 for the first time today, it of course has 3 of these style filters, which leads to a bit of information, and a question or two.

All 3 of mine have had the mesh strainers removed and replaced with what appears to be a section of white ceramic filter (looks like styrofoam) and appears to be roughly cut on the ends, has anyone seen these?

2 of the 3 leak at the base, does anyone know the size of the gasket on the bottom of these pumps, or a source for the strainer baskets (I have a spare pump and a spare filter strainer for my MEP-701a already, so just really need one more mesh strainer)? (I should have pulled one of mine off before it got dark here)

All three seem to run, but one is a bit noisy.

Ike

 

[RichardR]

Ike,
I have several Facet pumps with the new ceramic filters. I prefer the old mesh strainers but I suppose the ceramic works OK too. The strainers of either type and the gaskets should be readily available from the usual sources that sell Facet pumps. Do a search on eBay for "Facet filter" and you will find them for about $20 or less. Not cheap, in my opinion, but readily available.
Richard

 

[Uloadit]

what does the EMI filter do. i just cut one out and rehooked wth out the filter and it is running .will it go out later?

 

[n1oty]

EMI is short for electro-magnetic interference. An EMI filter is purposed to eliminate or suppress the EMI that tends to be generated by electro-mechanical devices that are turned on and off rhythmically and generate electrical impulses that can interfere with other devices. In this case, I presume that these gen sets are grounded and filtered so as to suppress any electrical pulses that may be generated in the radio frequency segments used by the military. After all, many of these gen sets are used to power comm, command and control centers. These filters are not necessary for the proper operation of the fuel pump per se, but may be critical if you want to keep RF hash out of the TV's and computers in your home when on generator power.

John

 

[RichardR]

Ike,

Just browsing around, I found the old mesh type strainers and gasket that fit the Facet pumps here for less than $6.00 + shipping. No telling what they want for shipping, but I would expect the total to be less than the eBay prices I mentioned above in Post #16.

And I should mention that all this info, and a wealth of additional details are in LuckyDog's WIKI here.

Richard

 

[Isaac-1]

Thanks. I saw them this morning but check out is broken so I will call in the morning

Ike

p.s. I ordered 5 of the filter/gasket combinations from Aftermark mentioned in the previous post, total with shipping came to $36