Thread: Priming a 300Tdi

Had this problem last year was stumped all day with it, then new got a new Lift pump an worked fine.

Reason why i think is that your lift pump is still working before under the pressure of the system but when you changed the filter you've released the pressure or something like that...

Anyway my suggestion is new lift pump.

I've never had this problem when changing fuel filters on either of my 300Tdi's. They generally just turn over a few more times on the starter before firing.

Here's a recent thread on replacing the mechanical pump, which is prone to leaking, with an electronic one if that's something you want to consider Joshua:

Replacing 300tdi lift pump with a Facet Posi-flo electrical pump


James.

Sorry I don't have anything really useful, but I changed my fuel filter not long ago and just turned it over with the key until it started a few seconds later. So I believe it what you did was valid... It's what I did at least...

Originally Posted by joshuah

G'day,
might be an air-lock at the pump?
Joshua.

Not a expert mate- my old man used to bleed a lot of trucks he had at the injectors i think. They would be much older

[ame="http://www.youtube.com/watch?v=XrWvH5nuCeA"]Yanmar YSE12 Diesel Engine Fuel Bleed and Start - YouTube[/ame]

Like this link and liked his filter. not sure if it of any use. Hope you wouldn't kick me if I mention my heart bleeds for you. Sorry my sick sense of humour

Thanks for the info. These things always seem to happen when you least need it. I guess better now than when 200km in the bush...

I now too suspect the lift pump, just buggered if I know why it would fail at the same time as a simple filter change. Brittle diaphragm?

And what's the difference between cranking the engine and using the hand-prime lever to move fuel? Does cranking do the same thing apart from allowing to bleed air out?

Anyway, maybe my land rover neightbour has some ideas. I'll hassle him tomorrow.

Thanks so far.

Joshua

Originally Posted by joshuah

Thanks for the info. These things always seem to happen when you least need it. I guess better now than when 200km in the bush...

I now too suspect the lift pump, just buggered if I know why it would fail at the same time as a simple filter change. Brittle diaphragm?

And what's the difference between cranking the engine and using the hand-prime lever to move fuel? Does cranking do the same thing apart from allowing to bleed air out?

Anyway, maybe my land rover neightbour has some ideas. I'll hassle him tomorrow.

Thanks so far.

Joshua

The Injector Pump will pull up diesel even if the Fuel Lift Pump is buggered, if you had of filled the fuel filter with diesel it probably would have worked.
Also did you remove and drain the water/sedimint filter at the rear, near the tank, try rotating the engine till you have some "feel" at the primer pump. Loosen a fuel line to the IP and pump till you get fuel, could take a while, Regards Frank.

Originally Posted by joshuah

And what's the difference between cranking the engine and using the hand-prime lever to move fuel?

I have read on this forum that the hand prime lever can move the diaphragm further than the engine moves it. So if a diaphragm is on its last legs, then being forced to flex a bit more than normal can be the straw that breaks the camel's back.

I have no idea if that is correct, but it sounds possible and I think a number of people have experienced failures after hand priming.

well, she's running as I type!

The neighbour couldn't get any prime either on the lift pump lever. So the last thing for me to try was filling the filter to the brim through the banjo bolt feeding the injector pump on the filter body.

About 10 seconds of cranking and she's running. It still leaves me to believe the lift pump may be failing?

I haven't taken her for a drive, but it's been idling for about 10 minutes so i'll have crack.

I think I might play it safe and get a new lift pump ASAP, though...

Thanks Joshua.

edit
However - after revving it for a bit, it seems to die away gradually and upon releasing the accelerator, almost cuts out - so I suspect the lift pump is not pulling its weight.