Thread: 1994 300tdi Fuel pump - location and fuse

there is a manual lift pump on the drivers side of the block...

they often let go and need replacing due to diaphragm damage

Just to add to Inc's post, there is NO other pump on a standard 300tdi.

There's a water separator thing back at the fuel tank, that's it other than pipes and the lift pump as mentioned.

If the system is sound and primed, the injector pump will suck fuel straight from the tank even if the lift pump is cactus.

Is the fuel solenoid operating ?

Originally Posted by Grizzly_Adams

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From my readings there are 2 fuels pumps in the 300tdi, a low pressure pump in the tank and a high pressure pump.

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Not knowing whats been done, firstly there is a 'low pressure' lift pump as already said front of block drivers side, the lever poking out the side of it is the giveaway.
The 'high pressure' pump is just the injector pump up front.

First thing I'd check is that there is no air in the injector lines whilst turning over. That is, with someone cranking engine over, crack each injector line at each injector, and make sure that fuel squirts out consistently, and not sputtering out.
Like a brake bleed.

other thing you can check is via the lift pumps priming lever, crack the small bleed nut at the top of the fuel filter and and whilst priming with the lever, watch for some fuel coming out the bleed screw.

Someone also mentioned the fuel cutoff solenoid, located at the back of the injection pump, has a spade connector and a wire to it.

One last thing to be mindful of is that some Tdis need some(or a lot) of glow plug to fire more readily. Mine just happens to be one of those that from stone cold, no matter the ambient temp, it always needs some glow plug time, when colder ambient(i.e. 15°C or less) it needs the full glow plug timing routine before it will fire up.

So I found the manual lift pump, and the level was/is digging a nice gouge in one of what I assume to be the injector pipes :-\

Anyway I'm just trying to see if I can manually pump some fuel into it, but I'm not sure if the crank is in the right position as it sort of 'clicks' (without the sound, but the feel) when I try to move the level.