Vacuum pump and fuel lift pump question

[GyroLandy]

I'm busy refitting some engine parts to a used '97 300Tdi Def motor I bought and have 2 questions:

1. In the manual it says i should ensure that the lever of the fuel lift pump is in correct position on the camshaft but it does not say how I will know whether it is. Does anyone know? Does the engine need to be at TDC or is it not necessary?

2. The manual says I should tighten the vacuum pump evenly to ensure it depresses correctly. Should I worry in what position the engine is i.e. TDC?

Thx

[Blknight.aus]

have a look at how the pump sits into the engine. if you put the "finger" on the wrong side of the cam it will be broken off or snap the pivot on the pump.

generically when I fit a lift pump I do the following

test the motion of the finger from its natural resting position, if the finger moves up towards the pump then it sits on top of the cam and the cam lobe will then actuate it towards the pump as the engine turns over

if it moves down away from the pump then the finger goes under the cam.

theres a heap of other things you should check if you are rebuilding the pump but when it comes to installation the main points to remember are to ensure that the finger is not engaged on the lobe of the cam when you install it (this is just a convenience thing you can install it while its engaging the cam, its just more annoying) and cleaning up the mating faces, installing new gasket material (and letting it set before you crank it up) and tightening the bolts up evenly and in stages.

I should probably also mention that it helps to hook the fuel hoses up to the right sides of the pump as well.

[GyroLandy]

I see the overhaul manual says there are 2 gaskets and a spacer for the fuel lift pump but I only saw one gasket on the block gasket kit.

Which is correct?

[Jojo]

What manual are you using? I don't know about any spacer and second gasket either. Mine is a ´95, though. Maybe two different types available (as with the oil plugs)???

[GyroLandy]

I've got the engine back in abd am keen to get her started today. I have bolted the lifter pump on but it doesn't seem like the lever on the pump makes any difference when I push it down. I doesn't provide much resistance which makes we wonder whether the finger isn't perhaps constantly under so mauch pressur from the camshaft that it remains supressed. I have turned the engine becaus I though it was perhaps just the way the lobe on the camshaft was positioned but no difference.

Perhaps all ss fine but I just don't know what it should be doing if it has been installed correctly.

Next question, which fuel line goes where on the lifter pump? There is a line coming from the fuel filter and one from the rear of the vehicle (presumably the tank) The top pipe of the lifter pump has an "In" arrow so I thought this would take the fuel line from the fuel filter but not sure?

[GyroLandy]

Anyone have a view on this?

[Blknight.aus]

the fuel flow on the filter follows the arrows.

the line from the tank goes into the arrow that points in towards the center of the filter and then the fuel pump pickup goes on the fitting with the arrow that points out of the filter.

if you cant identify which pipe is which from the tank use about 10PSI of compressed air and with about 1/4 of a tank apply pressure to one of the 2 lines in the engine bay. if you get a bubbling noise and air out of the other hose then you are blowing into the supply line, if you get a flow of fuel then you are blowing into the return line.

[GyroLandy]

Thx, just to be sure, the fuel flows from the fuel filter to the fuel lift pump?

Where does the other pipe go to from the fuel lift pump?

What does the fuel lift pump do?

[Blknight.aus]

the other pipe from the fuel lift pump goes to the back of the injector pump.

the fuel lift pump basically lifts the fuel from the fuel tank and puts it into the injector pump

the full fuel sequence more or less is

tank
fuel water seperator
filter
lift pump
final filter (if fitted)
injector pump
injectors
return line to tank