4 cylinder diesel fuel pump problems

[salve7]

I have a series 2a that is cutting out at 3/4 of a tank like it it is running out of fuel. I have replaced all filters and have checked the tank for any crazy slime and have found none. The "pickup" tube is free and clear of any problems which leads me to believe that it is the fuel pump. As I am bleeding the fuel system, the manual pumping lever moves freely without much resistance, maybe some pump feel for a 1/4 of the stroke unless I try cranking the engine again which sometimes gives the pump a better feel. Is this normal? I was told that sometimes the diaphragm can malfunction as the engine gets hot but it seems the issue really doesn't crop up until 3/4 of a tank. The previous owner was stumped as well but his solution was to just keep it filled. I am moving in a couple of weeks so I would like to get this resolved as quick as possible so I can use it to move my crap. Any help is appreciated. If it helps I have found that the battery is usually low as well when this happens, just by weird circumstance, but I have no reason to believe that this has anything to do with it other than pissing me off as I try to crank the engine after bleeding.
Thanks,
Jay

 

[Antichrist]

I think depending on where the camshaft stops when you shut down the engine it can affect the feel of the pump, if the lobe is against the pump arm.
The best way I've found to check it is to disconnect the supply pipe, hold your finger over the port and pump the lever. You should feel distinct suction at the port.
If it feels ok, drive it till it dies/stumbles and then try it and see if it feels the same. If it does, that would point to something else.
I'm assuming with the filler cap off it does the same thing.

 

[salve7]

By filler cap, do you mean the fuel fill cap? I will disconnect the supply hose and see what kind of suction I can get. The pump feel sounds like a legit reason however I rarely get a full pump from the arm at any time. I am prob going to put a new fuel pump on anyways because I am tired of chasing this down. This has been an issue since I have had it and I can't find anyone with a similar experience anywhere on the net.

 

[Antichrist]

Yeah, fuel filler.
You should be able to get a full solid stroke. Does sound like the diaphragm is going.
I haven't run across this problem either, at least not that I recall.

 

[salve7]

I am going to try a new pump. Could you tell me if this one will work? Kenny from BP said it would but I would like a second opinion as they are half the price of what I've seen most of them going for. I usually get the best but since I am moving I would like to save a little coin now and replace it again later when I have the funds. http://www.britishpacific.com/search.php?q=2.25+diesel+fuel+pump+

 

[Antichrist]

I expect it's just cheaper because it's an Allmakes, which isn't necessarily a bad thing. I don't have any experience with Allmakes fuel pumps so can't really comment on the quality/longevity.

 

[salve7]

Thanks Tom! Once again you have been a big help. I ordered the $30 pump so I guess I will see how long it lasts.