Priming a 300Tdi

[Intrepid]

G'day,

I thought I'd replace the fuel filter on my 1996 Defender 110. It's the 300Tdi.

I unscrewed the old one and after reading a few posts, simply screwed the new one in, assuming it would self-prime. It started okay, then spluttered after a couple minutes, and then died!

I can't restart it. I have tried to hand prime it at the lift pump, but I am not getting fuel to the filter. I have undone the banjo bolt into the fuel filter and no fuel is coming in. I have rotated the engine and the hand prime has some resistance, but no action to speak of...

I have had to walk away for fear of saying something the kids might hear, so in the meantime, can someone please give me some help? After it died, I unscrewed the new filter and it was still dry. I poured in a little diesel I had, but no difference.

I was thinking of buying some diesel and pouring it into the filter as all I can think of is that there might be an air-lock at the pump? Other than that, i'm stumped! Is there another way to prime? Ideas? I can't see why the lift pump would conveniently fail at the same time, so i'm not considering that, yet...

Joshua.

[hills boy]

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.

[rainman]

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 (http://www.aulro.com/afvb/technical-chatter/158780-replacing-300tdi-lift-pump-facet-posi-flo-electrical-pump.html)


James.

[Judo]

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...

[NavyDiver]

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

Yanmar YSE12 Diesel Engine Fuel Bleed and Start - YouTube

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:)

[Intrepid]

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

[Tank]

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.

[vnx205]

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.

[Intrepid]

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.

[weeds]

If it was running fine prior than maybe it is sucking air through one of the fitting s you have crack, might be worth double checking for tightness just incase

[Intrepid]

the bolts I can see are tight. I only loosed the bleed and one banjo bolt. The fact that I can't manually prime it, suggests to me that the prime/lift pump might be gone. After I turned her off and had another go at hand priming, I could see a few tiny bubbles intermittently, but nothing more. I would have expected fuel to flow out of the bleed hole, but this didn't happen. I can't really bleed the injector pump either at this rate, which may also have air in it.

I'll triple check it all though.

Thanks.

Joshua.

[rick130]

Try not to pre-fill the filter with diesel, you stand a good chance of introducing crap into the pump, and this coming from a bloke that always pre-fills oil filters ;)

[Reads90]

Mmm Tdi's are self priming engines so you don't need to prime them

So sounds like you have another problem. As said check linkage
Or in the change over you have disturbed something.
I have change loads of fuel filters on the TDi's and never had a problem.

[Blknight.aus]

your lift pumps gone and your engine is operating on the regulator pump integral to the injector pump.

The regulator pump works fine while its fully primed, once you loose prime or begin to draw air the lift pump is vital to keeping the engine running. the most common sign of drawing air through the fuel system is the injector pump rattling.

[Intrepid]

your lift pumps gone and your engine is operating on the regulator pump integral to the injector pump.



That's what I reckon too, now! I removed the lift pump and manually actuating the arm does nothing I can see. I put some soapy water on the inlet and outlet orifices of the pump when moving both leavers, nothing happened - no sucking or blowing of bubbles. I put a hose on the inlet hanging in a jar of diesel - nothing, even after pooring it in manually first.

I inverted it and pumped the lever and it actually jammed. I gave it a shake and I could hear loose bits inside rattling. Me thinks it's cactus.

I know a couple posts had suggested it already, so Kudos to you. ;)

I have ordered a new one, so *hopefully* it will solve all my problems!! All going well, I'll have 18 hours to put it together before my 3-day fishing trip. No pressure, Joshua!

Bloody poor luck that it failed at the filter change - the small amount of air must have been the final straw... Considering I have only had the car for 500km, so far I have had a pretty average run! Ho-hum.

Thanks guys,

Joshua.

[Intrepid]

Well, just to follow up...

The new fuel lift pump is in and fitted. All problems are now solved. I had some issues getting the olives on the fuel pipes on the lift pump. They needed much coersion and in the end I could only get on flush with the pipes. They seem to be too tight and force was damaging the olives.

Anyway, it's not leaking diesel and i'm priming again! Yee-ha.

Thanks for all the help all.

Joshua.