Fuel Pump priming whoes (2810)

For some reason or another, I just can't seem to get the blasted fuel injector pump primed. I have not gotten anything but a drop or two of diesel out of the middle fuel pipe that leads to the injectors, the other two are bone dry, and even the middle appears to have stopped its dribble. I have primed the fuel filter, and checked all the pipes leading to and from the fuel injector, except one, and I will check that one shortly in a minute or two.

Admittedly, one of the fuel lines has a cracked fitting that I have sealed with JB Weld and Seal All to hold me over a while, I also have an issue with the vacuum line that comes out of the top of the fuel pump, and it is sealed with petroleum resistant epoxy and Seal All as well. So, I have no visible leaks that I know of. Also, I am priming it after having replaced most of the seals and gaskets in the fuel pump, so everything should be fresh.

I open up the bleed screw on the side and I do get diesel flow in the form of a steady trickle, that does not change when I turn the engine over. You get a little splatter, but nothing begins to gush out as one would think it should. When I open the bleed screw on the other side and get the same result. It is starting to sound like I have a blockage somewhere, but where it could possibly be, I have no idea. There might be a problem with the vacuum line being clogged up.

Any tips, tricks, or help would be appreciated.

That CAV DPA pump has NO vacuum line. I'm not sure what you've done..

That line that you have plugged needs to be hooked to line on top of injectors. How long has this unit set ? If several months there is internal componets stuck is why no fuel at injectors.

I didn't plug it, it is as you say it should be. The vacuum hose goes from the top of the pump to the three injectors and up to the fuel tank. There is a line running from the air intake heater that connects to it via a 'T'-coupler. All of which are clean and should be fully operational.

<pre>

/*
* x
* x <--- TANK
* x
* x
* x----------+
* x :
* x :
* x +----------------------------------------------------+
* x : :
* : ++
* : ++ < Intake Heater
* :
* : ++-----+-+------+
* +-----------+++ +-+ ++-----+
* : : : : : : :
* : : : : : : :
* : : : : : : :
* : : : : : : :
* +-+ +-+ +-+ :
* :
* ^INJECTORS :
* +++
* :+:
* xxxx +----++-+-----+
* x x+-+----+ +-----++
* x x: :
* x + :
* x + PUMP :
* xxxx: :
* +----------------+
*/

</pre>

Have you checked for fuel delivery from the tank, through the lines and filter and then through to the Injector Pump (IP)?If the tank strainer is clear, the lines and filter head and fittings are clear, the filter is clean then fuel should pour out like a cow peein' on a flat rock. When you crank the engine, the fuel should squirt out of the IP bleeder, not dribble.

In all seriousness, I thank you for the lovely illustrations, they are exactly what was needed. All the terminology you read in the manuals becomes rather vague and ambiguous eventually, but when you mention phrases like cows peeing my mind exactly knows what you are referring to. For some reason, the first time I saw a cow peeing, I found it hilarious, I don't know why. So, it is a very rememberable image for me.

This answers some questions, the fuel is gushing out from the filter, but once it get's to the fuel pump it is dribble. Looks like I need to inspect those pipes and the internal net strainer for blockages.

Sincerely, Thanks.

Hot digity dang! I found it!

The regulating piston is getting stuck inside the fuel pump, and just needs to be cleaned and reassembled.

WELL...

After cleaning the regulating piston, I am still where I started. The pump, just, isn't priming like it should. I must have a leak somewhere that is allowing air to get in or something. I might pull out my compression test kit and see if I get good suction on the pump, this will tell me if anything is leaking, which would prevent the pump from getting primed correctly.

It still appears there is a clog in there somewhere. When I open up the bleed screws, what comes out is very little.

The tractor was sitting for a year, but the fuel does not appear to be jelly or anything. It looks like diesel.

I think there is a filter/strainer on the imput of the cav pump you might check that