Mep 803a fuel injection pump

[Glenn H]

I have purchased this unit and I believe the injector pumps have been tampered with. Could someone please help me with the correct assembly of an injector pump for a Mep 803A please here is the way it came apart ( attached is a picture ). Also the piston that is pushed up by the tapet can go in two different ways, which is correct? ( picture is attached ). A diagram would be Great as well.

 

[Glenn H]

I have purchased this unit and I believe the injector pumps have been tampered with. Could someone please help me with the correct assembly of an injector pump for a Mep 803A please here is the way it came apart ( attached is a picture ). Also the piston that is pushed up by the tapet can go in two different ways, which is correct? ( picture is attached ). A diagram would be Great as well.

I have received some assistance on another sight. Here is the correct order of parts and the correct way to install the piston in the injector Body. Pictures below. Thank you so much Uniquity for your help.

 

[Leonardo82nd]

I have received some assistance on another sight. Here is the correct order of parts and the correct way to install the piston in the injector Body. Pictures below. Thank you so much Uniquity for your help.

I’m curious about the stiffness of the lever towards the bottom of the injector. I ordered three sets of “new” injectors . Each from different vendors. Only 1 out of three units came with a lever that can be moved with little to almost no force (almost moveable by flipping the injector side to side) . The other two “new” units came just as stiff as my problematic injectors.
I’m going to test them all on a trigger pull scale. The reason I am replacing the existing injectors - is because the fuel rail was not strong enough to engage that lever. About how loose or firm we’re yours? And did you notice anywhere in the disassembly where that levers firmness could be affected / adjusted.

 

[Glenn H]

I’m curious about the stiffness of the lever towards the bottom of the injector. I ordered three sets of “new” injectors . Each from different vendors. Only 1 out of three units came with a lever that can be moved with little to almost no force (almost moveable by flipping the injector side to side) . The other two “new” units came just as stiff as my problematic injectors.
I’m going to test them all on a trigger pull scale. The reason I am replacing the existing injectors - is because the fuel rail was not strong enough to engage that lever. About how loose or firm we’re yours? And did you notice anywhere in the disassembly where that levers firmness could be affected / adjusted.

My pump lever were very loose, there is not really an adjustment for that, maybe a thick oil or grease they were pack in when new, I soaked mine in lacquer thinner wiped each part down and sprayed wd40 on them as I reassembled. Hope this helps, holler if I can be of any help.

 

[Light in the Dark]

Are these OEM pumps or aftermarket?

 

[Leonardo82nd]

Are these OEM pumps or aftermarket?

OEM, I ordered a total of (3) “new” injector pumps
all from different vendors.

The top injector (brown box) came with the bottom piece unattached. This is the unit that moves freely. The lever rotates with a flick of a finger .

The second and third (white boxes) are from two other different vendors. The levers are just as stiff - as the ones I’m replacing (bottom injector no box)

I ran into a significantly lower priced aftermarket brand named “holdwell”, but I haven’t found a trustworthy marketplace to order it from.

I am not sure what’s going on , but I’m uneasy about installing one that’s stiff - and running into the same issue. They’re pricey ($270-$340)

 

[Light in the Dark]

Well I've used HQ for parts before, and they are never OEM... they are knockoffs for the items I have purchased. They have been of sufficient quality though.

It doesn't help you right this second, but you should inquire with https://www.sleeman-hawken.com in the UK. They carry true OEM parts (and recently sold the actual LP company off, which they had bought after one of their countless restructurings).

If you don't mind me asking, what companies did you source the Stanadyne items from?

 

[Ray70]

One thing I would try is take one of the stiff pumps and compress it just about 1/8" or so and see if the lever frees up.
When they are installed there's a slight amount of preload on them.
I have see some that are stiff ( a little stiff ) in their free state, but free when compressed slightly because in the free state the spring is bottoming out the plunger and putting some friction against the fuel lever.
If they are still stiff I would not install until you figure out what's going on.

 

[69birdman]

I think I commented about a pair of Standadyne pumps I purchased back in August from Merlindiesel.com, located in the UK.
2 new pumps, 3 day shipping $225
The website pictures looked different, but the sales guy ,Ryan Walkden, opened one box and sent me pictures of the correct pump.

 

[Leonardo82nd]

Well I've used HQ for parts before, and they are never OEM... they are knockoffs for the items I have purchased. They have been of sufficient quality though.

It doesn't help you right this second, but you should inquire with https://www.sleeman-hawken.com in the UK. They carry true OEM parts (and recently sold the actual LP company off, which they had bought after one of their countless restructurings).

If you don't mind me asking, what companies did you source the Stanadyne items from?

The Stanadyne came from
- M&D Distributors (USA) $244 delivered

-merlin Diesel (UK) $272 per delivered super fast shipping

-The HQ was the most expensive $340

I’m going to try what @Ray70 recommended on the two stiff ones .

the pumps definitely move more freely with a bit of compression , thank you