mep-802 / mep-803 fuel pump mortality rate

[zarathustra]

Well, I got several facet fuel pumps 'cause I knew I'd need some, and I ended up with four of 'em -- all NOS.

Well, THREE of the four failed straight out of the box, and the fourth works fine! I took one of the failed ones apart and nothing looked obvious. Anyone have a fix for a new failed facet pump?

I read on the web that Facet cube pump failures are quite common, but no one has a fix for 'em. It seems to me that there ought to be some kind of fix, so let's see if anyone has any experience in making one of these work..

 

[m-35tom]

did you get them surplus? i have found lots of things that were surplused because they failed QC or had a known defect and they just throw them away, then someone sells them as NOS! what is inside? i have one of the round pumps that is shorted, but they are pretty cheap so i will just buy a new one.

 

[zarathustra]

Well, perhaps they failed QC, but they were dry, so the QC didn't involve pumping anything through it. This particular (40193) facet pump is kinda odd since it has such an unusual PSI and GPH rating -- sorta backwards from all the other Facet cube pumps.

There isn't much inside them; I'm going to fool around with that teflon ball inside of it and see if that is causing the problem. I hate to take a known good pump apart, but I might just do that to see what works differently in the good one.

I thought about substituting an auxiliary pump in it's place, but they are not the same pump, or at least the the GPH / PSI ratings on the aux pump are 180 degrees out from the 40193 pump.

I've never seen a circular one for sale...

Oh, I did get the 802a running yesterday -- it still has a few issues to work through, but at least it chugs along with good oil pressure and a constant running temperature thus far.

 

[zarathustra]

I took one of the "bad" ones apart, and here is a fix for them.

If one removes the OUTPUT fitting from the pump housing he'll see a plunger and spring. Take those out and look inside. There is a copper tube and inside that copper tube is a sliding metallic sleeve -- not the small 'cylinder' that the plunger goes into, but a metallic sleeve that is almost as large as the copper tube.

That sleeve should move freely. In 100% of the DOA NOS pumps that sleeve was stuck in position. The sleeve isn't supposed to come out, but it is supposed to freely move back and forth inside the copper tube.

So I used some PREP cleaner ( used in body shops to clean parts before painting) and worked the sleeve loose, tried it out and that previously bad pump came to life. One was really stuck badly and took a lot of finagleing (sp) to get it loose. On one I tried using the end cleaner from a tubing cutter.

Best I can tell is that the electromagnet in the pump housing turns on which causes the sleeve to move aft, depressing the plunger and spring AND allowing the plastic ball inside the plunger to move forward which in turn allows fuel to enter the plunger. When the electromagnet shuts off the spring drives the plunger forward; the plastic ball moves to block fuel from leaving the back end of the plunger, and the plunger forces fuel out towards the engine.

Hopefully someone can use this information -- this also should help on used pumps that have been sitting for some time.

z

Oh, and the latest 802a -- runs fine till it warms up and then starts "hunting". Haven't tried to solve that problem yet. I found Delphi injectors in it which did not fit snugly into the hole. I wonder if those could be causing me problems.

 

[m-35tom]

good job george! see, anything can be fixed.