Diesel pump firing timing, when placing new pump

[Viva_65]

Hey guys, so i got a new bosch pump for my 2.5 tdi.

Im trying to understand if i need to time the firing order and how?

Of course i can pin it. That works if when 1 revolution of the pump fires the 4 cylinders.

Is that how they work?

Thanks in advance to anyone that knows and take the time to respond

[metalworker0]

https://www.marinedieselbasics.com/wp-c ... ervice.pdf

timed on number 1 cylinder at 11 degrees before top dead centre.. (btdc)

number one cylinder at the front
crankshaft revolves twice to fire all cylinders

all the best.mark

[Viva_65]

Thanks Mark

I just read through and i couldnt find what i needed

How do i know that the new pump im going to fit is timed to fire the number 1 cylinder and not the number 4?

I say 4 because if the firing order is 1-3-4-2. Im guessing 1 revoulution of the diesel pump fires 1-3 and the next revolution will fire 4-2.

Maybe i missed it but i went through the manual 3 times. Thanks

[metalworker0]

You'll remove the rocker cover.
when cylinder 1 (at the front timing belt side) is on its firing stroke at TDC, both valves will be closed and you'll feel the looseness in both rockers on that cylinder.

So then the timing is lined up at top dead centre TDC cylinder 1 . if it isn't you turn the motor over another 360 degrees

Then it's the case of finding 11 degrees before top dead center, if i remember rightly, which is marked on the pulleys that you peg ......

according to the manual - ive just confirmed its timed at number 1 (not 4)

and if you cant fit both pegs you are out

Only rotate clockwise to archive this .. or you might undo the crankshaft nut.

Note: i'm reading what the manual says .. i have no experience with this engine .. and you are lucky to have a manual that is understandable and written in plain English by LDV .,. if it was written by ford .. i would be lost, as the ford manuals are USELESS.

all the best.mark

[Peterr]

Hey guys, so i got a new bosch pump for my 2.5 tdi.

Im trying to understand if i need to time the firing order and how?

Of course i can pin it. That works if when 1 revolution of the pump fires the 4 cylinders.

Is that how they work?

Thanks in advance to anyone that knows and take the time to respond

This has been my question too. Today I’m visiting a pump specialist. I’ll ask him if it enough to just rotate the pump until you can pin it, or if it’s a matter of maybe needing to rotate it twice to get it synced. The service manual shared above doesn’t mention this.

[metalworker0]

i see what you are getting at .. you're saying the pump could be 360 out, even though the timing is right

not enough experience to comment now

would have thought, that you just pin it with the timing right and everything else just sort of works out right. the pin hole sets it to squirt at number 1

my best guess is the pump sprocket goes around at half the speed of the crank

all the best.mark

[metalworker0]

OK done a few searches and confirmed, pump rotates at half speed .. basically with pins in the holes you cant go wrong, with :
number 1 on firing stroke as explained.

all the best.mark

[Viva_65]

Okay great guys thanks

Yeah for sure the pump runs half the speed as the crank ad the camshaft pullet and the diesel pump pulley are the same diameters.

Great this means 1 rotation of the diesel pump fires 4 cylinders.

[metalworker0]

yeah you got it

all the best.mark

[Peterr]

Just spoke to an old timer pump specialist here in Slovenia. Working since 1972! Knows everything just pin the pump your good to go when cam and crank are correctly pinned. Leave some slack on the pulley front plate so you can get the timing belt on correctly before torquing it.

[cherniy_chack]

I've installed Bosch pumps instead of Lucas EPIC pumps several times.
They are identical in installation.
Before removing the Lucas EPIC pump, all rotating engine parts and assemblies are mounted on pins, and the timing belt is removed.
Then, the Lucas pump is removed from the engine and the Bosch pump is installed.
The high-pressure line layout for Lucas and Bosch pumps is the same.
After installing the Bosch pump pulley on the pin, loosen the four bolts on the pump pulley and install the timing belt. Tighten the pump pulley bolts.
After bleeding the pump and lines, tighten the nuts on the injectors and start the engine.
After starting, injection timing adjustment may be required.
Loosen the four bolts on the pulley and use the nut on the rotor shaft to rotate the shaft clockwise to increase the injection angle (earlier injection) and counterclockwise to decrease the injection angle.

[Peterr]

Thanks! Clear and concise! Best explanation so far