Diesel Pump Will Not Prime

[Ian]

Posted on behalf of Patrick from Tyneside who has a 1995 diesel.

I've got a problem I can't fix. The van was running okay but developed a leak behind the fuel injection pump. Although it is an awkward job, I replaced the two seals on the domed cover and the blanking plate at the back. However, I can't get the pump to prime or deliver any fuel. I've loosened the pipes to two of the injectors and turned it over on full throttle, but after three days of getting nowhere and flattening the battery every day in the attempt, there must be something wrong. I know the thing is normally self priming.

One difference was that this time whilst the domed cover was off, a 'piston type thing' fell out. I'm pretty sure it must fit over the spring, (i.e. with the spring inside it) so thats the way I put it back. There is also the possibility that something might not be right on the other side, but of course you can't see that.

Any ideas? Any clue to what lies (or should lie) inside that domed cover? The drawings on the factsheet don't really show this. I'm getting a bit desperate now, I've run out of ideas!

One almost certainly unrelated query, but I found this connector (pictured below), terminating in what might be some sort of sensor, just hanging in space at the end of the pump when I started. It looks like it should clip onto something, but do you know where?

[g8dhe]

The plug (13-1552) with the resistor fitted is a means of configuring the pump for the vehicle see below for the table http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[Northern Bongolow]

have a read of this below its very similar to the bongo pump.
from memory the piston only falls out if your very unlucky and remove the side plates with the rotation of the pump in a certain position and a little peg that holds it in position falls out. ive heard of several people experiencing this but not heard how they fixed it sorry.

http://quietglow.com/dieselvanagon/Bosch_Pump/-Rebuild.

top tip and WARNING TIME.
DO NOT TAKE THE END OF THE PUMP WHILE ITS IN POSITION, THAT IS THE HIGH PRESSURE END WHERE THE INJECTOR PIPES FIT. IF YOU REMOVE THE 4 BOLTS AND TAKE OFF THE BLOCK YOU WILL END UP WITH A BUCKET OF BITS LIKE I DID. IT HAD TO BE REMOVED AND STOOD ON THE GEAR END TO BE WORKED ON.

there is a little clip that receives the block mentioned above, its on the side of the pump, its not where you think it would be so have a look in a stupid place

[Drpatrick]

Thanks for the messages about the connector/resistor. Although its not related to the fuel pump priming problem, at least its clipped back in its proper place now.

I found advice elsewhere that said the 'bit that had fallen out' goes in with the flat side to the engine. That looks a bit counter-intuitive, but I've put it back in that way for now.
I've also found a way to solve the priming problem. Again following advice I'd found, what I did was take the fuel return line off (thats the one on the upper left of the pump as you're looking at it) and stick a hand operated vacuum pump (a cheap plastic one made for removing fluids from engines) onto the fuel pump outlet and sucked first the air and then diesel all the way through the pump, then quickly clipped the fuel return hose back on. It then took about three attempts to start the van, but it was trying to fire straight away.

Thanks for all the advice!

[Bob]

Splendid.

[rita]

Good result