MEP 002A not starting

[trdshowal]

Hello All, newbie here, I got a mep002a, changed all filters, the replacements are 1/4" shorter will that be a sealing problem ? I'm missing 1 centering mount for filter, fuel isn't filling the filter bowls up (flushed tank & lines)cleaned out pump filters in base also so thinking the fuel pump isn't working properly, it clicks at a slow pace as the aux pump is quick at first then slows any advice ? or anyone know where to get a new replacement ? also need an air hose off the air cleaner. Thanks

 

[Isaac-1]

A couple of things here, first the fuel pumps have a removable base with a cleanable strainer inside (replacement strainers are available also) check to make sure it is not clogged up (the end should have a place to turn with a wrench it comes off kind of line a child proof medicine bottle twist lid). It sounds like yours is working right, fast clicking until it builds pressure, then slow clicking, If you need to replace them as was mentioned in another message thread last night the electric fuel pumps on these generators are Facet Purrolator Gold-Flo pumps with a special military plug, if you don't care about staying original these pumps are available at many auto parts stores such as NAPA, just make sure to order the correct 24V variety and splice on the plug. (these pumps are also very popular for marine and industrial engine application where 24V is more common)

Ike

p.s. are you leaving a downstream connection open to let the air out when trying to get the fuel pump to fill the filters? With diesels it is very important to bleed all air out of the system all the way to the injectors.

 

[trdshowal]

I cracked the inj lines at the pump and cranked it 5 TIMES FOR 15 Secs. nothing... I then filled the filter bowls up with ATF to help purge the lines still nada should the pump only click at a slow rate ? the Aux starts out fast then slows down thinking of switching the aux to the pri position

 

[Isaac-1]

Do you have fuel in the line going into the pump? If the pump is worn it may be loosing some of its ability to self prime (I think the dry priming lift on these pumps is rated at somewhere between 12-24 inches). These are fairly low pressure pumps (I think around 5 psi) , and should slow down when back pressure builds up. Any small clog in a elbow fititng, etc can block the fuel flow, pressure from the electric fuel pump is probably low enough that you could block it off with your thumb. As to finding the problem I would:

Disconnect the fuel inlet to the pump and see if there is fuel coming in
If there is then I would diconnect the output line, apply voltage and see if anything comes out.

If not make sure to open it up and check for stuck parts (make sure the ball in the center springs back if you tap it)or clogged strainer, the working parts of these pumps are very simple.

Ike

p.s. I just went to look at a spare we have here for an Onan generator, the end cap "nut" is a 5/8 inch, not all have the nut on the end which makes removing the cap easier

 

[trdshowal]

no fuel to pump I blew out all lines, but not the pump thinking it would damage it ,cleaned screens & came out fine, but not the pump guts should I try to remove them nothing to damage wiring etc.? happen to know about the cost of a new unit ?

 

[Isaac-1]

Retail is around $90 or so, I have never taken the guts out of one, but have seen an exploded diagram in a parts manual with individual part numbers for the components so in theory it was designed to be repaired. Behind the retaining clip is a washer and maybe a gasket or O-ring followed by ball or cup, a spring and a piston (there is also a small magnet which may be in the end of the cover or after the clip, the diagram is not clear and I am at home now so don't have an easy to access one available. If it is not pumping you don't have much to loose, may just be gummed up preventing the piston from moving. If you unmount it and provide power (with ground) it should try to oscillate in your hand (think the shake weight commercials on tv)

 

[coyote62ny]

if you need fuel pumps try tom at gulf coast trucks office 1-281-422-3200 cell 1-832-323-1445 good guy to deal with and very helpful

 

[treeguy]

Trdshowall, you said at first that your low pressure pumps would click and then slow down, that sounds about right as said before. I don't know if your know so sorry if you do, to start the mep's you have to hold the master switch in the preheat position for a good 30 - 60 count, then turn it to Prime/Run, when the clicking slows down its time to start. I had a very hard time starting mine after the previous owner let it sit. I had fuel to the Injector Pump (IP) but none from the injectors or out of the IP. Check this thread - "My first mep-003 start" This was what was wrong with mine, I can't imagine that once you get the low pressure pumps back together that there is much else to prevent no start up (clogged/stuck injectors). If it starts and stalls when you let go of the master switch its because you didn't hold it long enough to build up oil pressure. These unit have "fault sensors" (can't think of the right word) that will actuate the electrical plunger on the IP to kill the fuel. There is also one for over heat. As far as I know there is some sort of starter lock out that will prevent frying of the starter while it builds oil pressure. Sorry I don't know how to set up a hot link to go to that thread. Good luck, there are a lot of good guys here that know these machines very well, they'll help get it to run or you can search other threads too.

 

[randyman]

The pumps are pretty simple. I had two that weren't working. Took them apart and cleaned them up good with carb cleaner to get all the gunk and varnish out. Now they work great. Just remember how they come apart and put them back together the same way-not much to go bad with them except getting gunked up. Good luck.

 

[trdshowal]

the auxiliary pump, pumps fast , then slows, the primary main pump just clicks at a steady slow pace never fast as the aux. I did preheat before cranking it over, oil pressure gets up to 30 PSI WHILE CRANKING IT OVER it sat for 5 years before I got it and me flushing out the fuel tank & lines

 

[Nonotagain]

With the fuel pumps runninig, break loose the line from the fuel pump to injector pump and see if you are getting fuel. If no fuel, start breaking the lines closest to the pumps and work your way to the IP.

Once you get fuel to the IP, then you get to bleed the lines on the IP going to the cylinders, one at a time. If you don't get fuel out of the IP, then the IP will need to be removed to be cleaned (if lucky) otherwise you might need an IP.

I'm leaving out a few steps, but you have to start at the begining and work your way up stream.

Just my .02

 

[trdshowal]

OK I got fuel after cleaning out the primary fuel pump with carb cleaner up to the IP but nothing threw it as of yet, I cracked lines on it & cranked it over 6 times for 15 sec. ea. nothing so.... next is removing the I.P. and spraying it too with carb cleaner ? or ...?

 

[panic_button]

Check the cut off lever on the IP to make sure it moves freely. I had the same issue as you and mine had a broken rod end and it took me 2 day to figure it out.

 

[treeguy]

Trd, I had the same prob., the mechanical guts of my IP were all gummed up from sitting and when I tried to start it an internal cross washer exploded. Did you read the thread I mentioned, PM me and I'll try to guide you.

 

[trdshowal]

no I didn't, but OK, i'll try to catch ya on line to I.M. you, it is about all that is left to get her to fire up & run unless the glow plugs are shot too !I would love to :

 

[treeguy]

I have attached the repair TM for the MEP002A, if you check adobe page#'s 135 to 146 or TM page 7-30 to 7-41 it shows the IP removal and repair. You IP guts most likely will NOT look like the diagram. Before you remove it from the genny block, crack loose the 4 allen bolts and crack loose the nut looking thing in the center on the front of the pump, this is the delievery valve, then take off the IP. I hope you have not taken off the nut caps on the injectors and used an allen wrench and turned the injector adjustment pressure, DON"T turn the allens. This is how to dissassemble the injectors, but you need a test machine that I don't know know where to locate. Do you have an arbor press? To take the IP appart, remove the four allen bolts, take out the cup plunger that the cam lobe rides on that is in the center of the drive gear on the back, it has a lip, pull with your finger nails or gently pry with a screwdriver, it is just slid in with oil suction and tight tolerances working against you. Under this is the timing button, with a snap ring, use a point tool to work it out. Under this is the drive shaft that at this end is cup, lock teeth, ring plate. What? There is a spring that has the drive shaft in its center, on the top of the spring is a mounting disk with keeper teeth that bite into the drive shaft. When the engine spins it turns the drive gear that operates the timing of fuel delievery, the cam slapping on the timing button pushes the drive shaft in and out like a piston which presurizes the fuel to go to the injectors. The drive shaft is round except for one side which is flat that a drive washer is turned by. The drive shaft/piston has to turn to open and close ports to send fuel to the right injector. So heres the deal; however you can compress the spring plate to release the two keeper teeth on the drive shaft/piston, pull the two teeth out, take off the spring plate, and spring. There may be washers throughout this unit that I am forgetting about, KEEP TRACK. Take off the delievery nut on the front you loosened, there is a spring, needle, maybe a shim washer here pay attention. You need to be sure to take out the throttle control lever, there is a keeper bolt and plate, the lever will slide out, but may be stuck. Take off the four allen bolts on the front, the internal frame is a cylinder inside of the square housing. With the throttle linkage off, if anyone doesn't disagree, gently press the drive gear tward the outside to get the drive gear internal assembly to slide out tward the delievery valve side. This internal cylinder is held tight to the outer housing by the pressure of two O rings to seal in the fuel. NOW, check out how it looks, there is a keeper snap ring channeled C clip that holds the drive gear to the internal unit. Gently pry this off keeping it in line with its self not to warp it. You should now be able to remove the drive gear. What is probably the root of your issues is the cross drive plate that the drive gear turns to turn the "dog house shaped piston shaft". You need to free up this shaft, it should spin and pulsate in and out hense presurizing fuel at the delievery valve. You need to slide out this piston shaft but there is the throttle donut in the middle cavity that has to go on ONE way ther is a dimple drilled on one side, put it back facing the same way! I had to carefully pound out the piston shaft, its all tight tolerances but should be free enough to slide and spin. What is under the drive gear? There should be the cross shaped washer, is it broken in two? It needs to be welded and ground back to shape, like I said this allows the drive gear to turn the shaft while the cam lobe pulsates the shaft in and out. Clean everything and assemble lubricated with diesel fuel and the O rings with vasoline or grease. Did you notice the tit on the inside of the throttle linkage, this rides inside of the channel groove on the donut, when reassembeling you must make sure the tit goes into the channel. The two O rings on the cylinder housing are delicate to reinstall with out shearing them off. Doughnut right way, throttle tit in doughnut channel after cylinder pressed into mounting housing, carefull O ring press into housing. Install cross washer, drive gear and its C clip, compress piston spring and install keepers. There is a screw on the side of the IP housing with a copper washer, remove screw and turn drive gear until a thin wire catches into a timing slot in the drive gear, that is what is the slot on the side of the gear. This is for timing the IP to the engine. Keep the gear and wire in this position for install. The engine needs to be turned so that the #1 cylinder is on a compression stroke with the PC marking on the pointer to the left of the IP on the block. Read the TM on timing the pump. You can turn the crank with the nut on the front of the air intake fan. Direction to turn to suck air into the motor. If you remove the #1 injector you can see if the piston is up. The PC mark will line up on a compression stroke and an exhaust stroke so you need the piston up and the cam lobe in the position of pushing onto the timing button on the IP. Read the Tm. This is not precicely order of work but its the basic idea, you''ll see how to go when you LOOK at things when you take them appart. Tight tolerances and need to be lubed with fuel. What did I miss? Yours was probably gummed up and stuck and probably blew the cross drive washer. Good luck, let me know how it goes, keep it CLEAN.

 

[trdshowal]

WOW Intense & Heavy reading Man if I Don't have a Choice i'll try this but... if i can get another Good Used or Rebuilt one i think i'll leave it to a Pro & my Luck I'd screw it up and the time wasted doing so would just add to my Misery but THANKS for all the info, I had no idea they where so complex was hoping for another can of carb cleaner fixing it ! like the fuel pump SHOULD I TRY A USED OR JUST GO REBUILT ? ANY SOURCES that are Reasonably priced ?

 

[Isaac-1]

If you do end up replacing the injection pump, try to get one that will match the timing button on the one you have now, otherwise you will end up spending another $70 for a matching button as they are sized to the individual pump for timing. For some reason a lot of shops will sell these pumps and tell people they can reuse their old button regardless of the measurements on the replacement.

Ike

 

[trdshowal]

so is that true or not using your old button ? know a good source ?

 

[treeguy]

I found out the hard way that they have no button. New pump, installed, NO GO! Man was I mad, I had no idea what was the problem, it didn't run on the old one, didn't run on the new one, and this was after a month and a half of tracking down everything else. Just the dumb button! So out of frustration and what do I have to loose, I dissassembled the old pump and found the broken cross washer. If you want to dissassemble the injectors I HIGHLY recomend you count the threads or turns to remove the allen cap under the 1" cap on top of the injector housing. The allen cap holds the precise spring pressure exerted on the injector pin. You can crack the allen PLUG that is on the very outside to bleed out air, or crack the high press. fuel line on the top. Trd, don't be afraid to take the pump appart it is a very simple design. The hardest parts are pulling the cylinder out of the housing because of the tight fit, compressing the spring to remove the keepers on the piston shaft and reinstalling them later, and getting the throttle tit (its more like a T now that I think of it) to line up with the channel in the donut that slides on the piston shaft to open or reduce the opening to let in more or less fuel. I have a brand new pump with NO button and it needs the proper delievery valve spring which could be swapped from your old one. But for the cost (I think it was like $400) I would take appart what you have and clean it.