MEP-003 recovery and adventure

[Dock Rocker]

Ok. We have our first hurdle. I have a no flow situation on the fuel system.

It appeared that I was not getting any fuel to the IP. I backtracked and it does not appear that I am getting any fuel flow at all.

Here is what I have checked so far. I have been using the TM to get as far as I have but I have hit the end of the road. Any help would be appreciated.

I installed the tank and I have confirmed that the pickup tube is in the number 1 hole (closest to the fuel filler hole). The routing of the hoses is as it should be per the TM. I blew the lines out but pulled one at a time and reinstalled them before moving to the next hose.

When I turn the switch to the Auxiliary pump I hear it kick on. When I go to prime/run I get no noise from either the #1 or #2 fuel pump. Also no fuel flow on the outlet side of either pump.

I tested the wiring and in the auxiliary position the auxiliary pump has power. It kills the power to the auxiliary when I go to prime / run, so that's working.

When I go to prime / run there is power going to the switch at the fuel pumps. See pic below

I cannot confirm that there is power coming out of the box in the pic and to the pump. I am not sure how that unplugs and I don't want to damage it. There isn't a plug going into the fuel pump to check for power there. The wire goes directly into the pump with no connector.

This unit was confirmed running before I broke it down to clean the fuel system.

I am going to download a few more TM's and see what I find.

Any help would be appreciated.

 

[jamawieb]

Take the bottoms off the pump and spray carburetor cleaner all in there. It's more than likely the pumps are gummed up.
The connections to the pump just pull apart at the black connectors (yours are painted green) that are located about 8 inches from the actual pumps. In your picture they are located out of the site of the camera, to the left, you can barely see the back of the connector in your pic. Try to twist them in a circle before pulling on them, also spray with a little WD-40 for lubrication.

 

[Dock Rocker]

Take the bottoms off the pump and spray carburetor cleaner all in there. It's more than likely the pumps are gummed up.
The connections to the pump just pull apart at the black connectors (yours are painted green) that are located about 8 inches from the actual pumps. In your picture they are located out of the site of the camera, to the left, you can barely see the back of the connector in your pic. Try to twist them in a circle before pulling on them, also spray with a little WD-40 for lubrication.

I pulled the filters out of the bottom of the pumps but I didn't spray anything in them. I will give that a whirl at lunch.

I have pulled the weather pack connectors off just ahead of the pumps. That's where I checked for power. The ones that I cannot remove are on the box, I am guessing some sore of solenoid, that the wire goes to from the weather PAC connector. That is the box pictured.

It has a soldered connection at the top that is under a threaded cover that looks kind of like a weather PAC connector but it's metal. And it does not look as though the bottom connection can be removed, but I could be wrong.

 

[Guyfang]

You are not wrong. They can not be disconnected.

Now take a breath.

One pump comes on. The Aux pump. So, disconnect the other two pumps, (at the rubber connectors, like jamawieb told you. Then, one at a time, connect the other two electric fuel pumps, to the one hot, (Aux pump) wire, to see if they will run. And yes, spray some WD-40, or carb cleaner into the bottoms of the pumps. That way you can see/hear if they come on. Then, put the S1 in the run position, and see if you have 24 VDC on the two cables that you removed from the normal electrical fuel pumps.

You can also take a wire, and go from the POS side of the slave recpt. and go to the electric fuel pumps, to see if they come on.

 

[Dock Rocker]

I did swap the known good lead from the auxiliary pump to both pumps and got no joy.

I went and hijacked a better tester and I know that I am getting power to the pumps through the boxes I pictured.

At this point I am thinking grounding issues. It seems that I am getting power to everything that's supposed to have power. Since it ran last it has been loaded onto and off of a trailer and jostled around some.

I assume that it gets ground through its connection with the frame since there is no ground wired connected. Also the Star washers that Guyfang mentioned earlier scream body ground as well.

I pulled the fuel pump assembly off and I am going to clean all of the areas that the metal meets on both the switch boxes and the fuel pumps themselves. This should get me a solid ground.

Is there a prescribed method for bench testing the pumps?

Looking at them from the bottom where the screen goes they are pretty clean as are the screens themselves. I sprayed them down good with carb cleaner just for good measure.


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[Dock Rocker]

Well it looks like I have two dead fuel pumps.

I pulled the assembly off and broke it down in order to clean the metal up to insure good grounding. After pulling each pump off of the bracket I took them individually to the genset and plugged them into the known good auxiliary pump plug. I took a ground off of the main ground lug on below the panel and ran it directly to the fuel pump housing.

The first one I tried was the auxiliary pump and as soon as I touched ground to it it pumped away.

I did the same thing with the #1 and #2 fuel pumps and nothing happened.

How in the world did I smoke two fuel pumps at one time????

Any thoughts on any other reason this would happen or how to fix it? Could they both be so jammed up with crud they want even buzz?


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[jamawieb]

If they are gummed up, you will not hear anything. I use nearly a can of cleaner on the pumps when they are gummed up to break them loose. Most of the time I will just take the main fuel hose off the tank and fill it full of carb cleaner and let it sit after I have cleaned them with the bottoms off.
Also, the boxes that are part of the pumps, that you referenced earlier are capacitors and are not needed for home use. They sometimes short and will not allow the voltage to get to the pumps but usually the DC breaker will keep throwing when they short. You can cut those capacitors out and splice the wires back together. You may want to try that before throwing them away.

 

[Dock Rocker]

If they are gummed up, you will not hear anything. I use nearly a can of cleaner on the pumps when they are gummed up to break them loose. Most of the time I will just take the main fuel hose off the tank and fill it full of carb cleaner and let it sit after I have cleaned them with the bottoms off.
Also, the boxes that are part of the pumps, that you referenced earlier are capacitors and are not needed for home use. They sometimes short and will not allow the voltage to get to the pumps but usually the DC breaker will keep throwing when they short. You can cut those capacitors out and splice the wires back together. You may want to try that before throwing them away.

I just hosed them down with break free and krull oil. I filled them as full as I could through the upper and Lowe ports. I am letting them sit for a day or so. I will see what that does.


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[Dock Rocker]

Just in case they are dead does anyone have a source for a new pump or two?


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[Guyfang]

There are some old threads on the electric fuel pumps. Sources and suggestions. Do let the pumps set for a day or two soaking. To many people toss a pump out, without giving them time to loosen up. The darn things cost too much.

 

[steelypip]

Diesel fuel plus water often forms a gum (bacteria love the stuff). These Facet pumps work by having a solenoid operated slug with a check valve in the middle bounce back and forth in the fuel line. If the slug is stuck to the bore nothing pumps.

Because the pumps use a Hall-effect switch to turn the solenoid on and off, they're incredibly reliable but for the gumming-up issue. So soaking in solvent to clean the gunk out of the check valve and unstick the slug is all you usually need.

The only other common failure mode is the RF noise filter capacitors (condensers) between the power wire and ground, which fail shorted and keep the pump from working. In this case you can disconnect the cap and get the thing working again.

 

[Dock Rocker]

Diesel fuel plus water often forms a gum (bacteria love the stuff). These Facet pumps work by having a solenoid operated slug with a check valve in the middle bounce back and forth in the fuel line. If the slug is stuck to the bore nothing pumps.

Because the pumps use a Hall-effect switch to turn the solenoid on and off, they're incredibly reliable but for the gumming-up issue. So soaking in solvent to clean the gunk out of the check valve and unstick the slug is all you usually need.

The only other common failure mode is the RF noise filter capacitors (condensers) between the power wire and ground, which fail shorted and keep the pump from working. In this case you can disconnect the cap and get the thing working again.

Thanks for the Intel. That makes sense.

Do you know of any solvents that are more effective than others. I am currently using a mix of krull oil and PB blaster. I filled the top half of the pump (opposite side from the filter) and let it sit overnight. I will try it out when I get in tonight.

I was a little hesitant to use anything that's more harsh because there is quite a bit of plastic in the pump.

 

[Guyfang]

Dock Rocker, give it a chance. One step at a time. You also need to check out the solenoid that you find next to the AUX pump. It can also gum up. If it dosnt work right, your ability to pump AUX fuel just went out the window. So give it the eyeball. Test it.

 

[csheath]

Good ol WD40 is hard to beat for a light cleaning solvent. If it doesn't come back to life would this pump work?

 

[Guyfang]

I cant tell you that. The NSN comes up as a M1 tank part. I guess you have to look at the data sheet that comes with it, and compare the input, output fittings.

 

[jamawieb]

Google: Facet 480517E
They run about $120. I would just replace 1 of the pumps, the fuel hoses will reach to reroute for 1 pump.

 

[steelypip]

Good ol WD40 is hard to beat for a light cleaning solvent. If it doesn't come back to life would this pump work?

If it's 24V, yes it will work. I used the 12V version of that for years on a much more demanding application than a 30 hp generator.

 

[Dock Rocker]

Well I just broke into one of the pumps to see what's up on the inside. I figured I would either fix it or it would be just as broke as it is now.

I took the check ball out and cleaned the plunger assembly with some Emory cloth. Everything looked pretty good. Not as gooped up as I thought it would be. I cleaned everything off and sprayed it down with brake cleaner then lubed it up and re assembled.

I had high hopes that were dashed. I went directly from the battery and again got no joy. I cut out the capacitor and got the same result. Apparently it is in fact dead.

I am going to order up some replacement parts and get on it again in a few weeks. Next week belongs to a summer camp getting to tell + or - 150 4th through 6th graders about the lord. It should be a hoot!


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[Dock Rocker]

Got the new fuel pumps in from Pegasus Racing early last week. They are awesome to deal with by the way. If anyone needs these pumps they are very nice with extremely prompt free shipping.

I finally had some time last night to re-mount the pumps and re plumb everything. This morning I got everything back on the genset and got all the lines blead.

As of now she is purring like a kitten. A very angry loud kitten!





Now that it's running and showing good oil pressure I can move on the the stuff I have no clue about. I am going to have to call in a chip to a few electrician friends of mine to help me sort out how to wire this thing up and make it convenient to run a 50 amp plug set up off of a camper.

I did notice that this needle was dead as a rock. It didn't move at all. Is it supposed to move with no load?

 

[jamawieb]

Got the new fuel pumps in from Pegasus Racing early last week. They are awesome to deal with by the way. If anyone needs these pumps they are very nice with extremely prompt free shipping.

I finally had some time last night to re-mount the pumps and re plumb everything. This morning I got everything back on the genset and got all the lines blead.

As of now she is purring like a kitten. A very angry loud kitten!





Now that it's running and showing good oil pressure I can move on the the stuff I have no clue about. I am going to have to call in a chip to a few electrician friends of mine to help me sort out how to wire this thing up and make it convenient to run a 50 amp plug set up off of a camper.

I did notice that this needle was dead as a rock. It didn't move at all. Is it supposed to move with no load?

From your picture, you need to bring the Hertz gauge up to 60 hertz. Increase the throttle to bring up the hertz. Your load meter (center gauge) will not move until loads are applied.