F6L912 Injection-pump TIMING

[bad sector]

My european model (rare in Canada) 1991 Dx-6.05 is coming along slowly. The engine is close to 'rollout' but I'm stuck with the injection drip-timing. The procedure in 'the book' shows a small hi-pressure hand-pump being used but doesn't say boo about the acceptable pressure-range!

The only such pump I have is an injector testing pump that's good for 9000psi and that could be overkill ..it could also destroy the injection-pump.

I've been looking around for such a pump but can't find any, of course not knowing the pressure-range doesn't help either.

Anyone know that pressure-range and where such pumps are sold (in 2024)? I'm also not sure about the exact sequence of what to expect seeing coming out of the drip-tube:

- when is there flow
- when is there nothing
- when is there a first drop or a last drop.

Thank you.

 

[swd40]

Hi,

just for the records: Your pump is for checking the injectors (100 bar+, I guess on the DX series its about 250 bar on the injectors).

The lift pump on the injection pump generates somewhat about 1 bar and this is what is fed by the hand pump. So if it does some 2 bar it's OK, anything above this is well overkill. The real pressure is generated in the pump itself, the lift pump just does make sure there won't be any air inside the outer housing. And I guess the easiest thing is to grab one of the electric lift pumps instead of that hand pump to ensure that any air inside the fuel lines and the pump is removed.

Regards,

Josef

 

[Stihl_026]

Hi,

n this thread we talk about setting the commencement of delivery of the hand pump with up to 30 bar (435 PSI )

Förderbeginn einstellen von kfrptr

Anleitung von Ölhand "Motoreinstellung"

 

[swd40]

Hi,

... and yes, 'Förderbeginn' matches 'injection drip-timing' ... didn't realize that is what you want to check/set.

There's various ways to do this. I just did with the 'blasmethode' on my D40.1s (F3l712). See Method 3 of Motoreinstellung

Short translation/summary:
- unmount pressure valve at injection line for cylinder 1
- put some hose on the injection line 1 and end it in a glass of water
- put a compressor line (0,5 bar is enough) at the fuel input of the injection pump (you can also blow into the line but I recommend not doing that ...)

As long as it generates bubbles it is not pumping (should decrease as you get near the drip-timing), as it stops it is on drip timing (will stop as you further turn the motor so at stopping is the point you want).

Regards,

Josef

 

[bad sector]

Thank you very much for the responses, I've seen 2-3psi as well as 200-300psi in assorted sources. I wanted to know in order to preclude damaging my injection-pump. I do have several electric lift pumps on hand so THAT's a relief! I'll have google-translator help me with those articles and I'll be back. Thanks again!

 

[bad sector]

Wow, air-bubbles, nothing to clean up, I like that one. Looks like a lot of reading coming up

 

[bad sector]

Hi,

just for the records: Your pump is for checking the injectors (100 bar+, I guess on the DX series its about 250 bar on the injectors).

The lift pump on the injection pump generates somewhat about 1 bar and this is what is fed by the hand pump. So if it does some 2 bar it's OK, anything above this is well overkill. The real pressure is generated in the pump itself, the lift pump just does make sure there won't be any air inside the outer housing. And I guess the easiest thing is to grab one of the electric lift pumps instead of that hand pump to ensure that any air inside the fuel lines and the pump is removed.

Regards,

Josef

It's a new injector test-pump, haven't used it yet and I just looked at the gauge

If the hand-pump in the service manual is only good for the equivalent of a fuel lift-pump then maybe it should not be called a high-pressure hand-pump.

If the lift-pump can do the job then all I have to do is hand-pump IT using the priming lever, no?

If I sound a little stupid it's because I have NEVER done anything like this. The last Deutz I built was in 2008 and it had a good pump so I just punch-marked and put it all back together exactly the same. The only other Bosch pump I ever did was on a Cummins and that engine makes everything very simple and very easy (timing pins on flywheel and inside the pump).

 

[bad sector]

I have chewed my way through the excellent and very informative translated articles and (because my injection-pump is a fresh professional rebuild) I don't want to start removing the pressure valve. This leaves only the canonical service-manual method aka. the high-pressure method requiring a 30bar/430psi hand pump (which I do not have!). I have upped the english content of the 23 steps of this method for reference (see links at bottom).

The image shows a plugged relief port #1, a ready-to-receive inlet port #2, and a drip-pipe #3. Sonce the pressurised inlet supply will be up to 435psi I think that plastic hose extension will have to be replaced.

There remain just a few questions that I need to confirm/clarify because I really don't want to mess this up:

The drip-pipe (orange) is really nothing other that the lower half of any injector-pipe?

Nothing is removed from the injection-pump #1 outlet port other than the (white) operational #1 injection pipe?

After having backed the crank about 90 degrees from compression TDC, what do I expect to see while pumping, nothing or a flow?

What do I expect to see as I reach the C-of-D point, do I see a last drop or a first drop just forming?

What do I expect to see as I veer the crank further PAST the C-of-D point?

Anyone know where I can get a 430psi hand-pump?

Thanks a meg for any wisdom

Ref: trhe official Service-Manual steps:
s01

https://imgur.com/mW4MzNm

s02

https://imgur.com/GmCbGbo

s03

https://imgur.com/TOoIbUS

s04

https://imgur.com/nQFXzsF

s05

https://imgur.com/iRE5UUp

s06 https://imgur.com/6P6Iq06.png
s07 https://imgur.com/6BCPqSc.png
s08 https://imgur.com/mkOD4z1.png
s09 https://imgur.com/U2Dr2ui.png
s10 https://imgur.com/Gg9RHyY.png
s11 https://imgur.com/EsYw2Ft.png
s12 https://imgur.com/gLosGqG.png
s13 https://imgur.com/T9DVnos.png
s14 https://imgur.com/i1zf7aC.png
s15 https://imgur.com/7jwHcNb.png
s16 https://imgur.com/VWx6f6k.png
s17 https://imgur.com/yTqJcsN.png
s18 https://imgur.com/aYvL4HM.png
s19 https://imgur.com/9IWpmKm.png
s20 https://imgur.com/TLLSH1n.png
s21 https://imgur.com/3HNGWku.png
s22 https://imgur.com/xdAPOQX.png
s23 https://imgur.com/hzEL3ui.png

 

[bad sector]

I found a pump meanwhile, it's a bit more then what I need but it can also be used to pr-test or even operate hydraulic circuits

https://www.beamnova.com/cdn/shop/products/b10af7a1-0683-4d85-9776-16209bcca676.jpg?v=1656384850

 

[bad sector]

My apologies BTW I wanted to insert only link-text and NOT live links which ended up making a mess (that's why I prepended each of them with the step #s). These links are probably useless for german owners anyway but I cannot edit out the links.

 

[swd40]

My apologies BTW I wanted to insert only link-text and NOT live links which ended up making a mess (that's why I prepended each of them with the step #s). These links are probably useless for german owners anyway but I cannot edit out the links.

Hi,

these steps are in http://amoko.free.fr/Documentations/Moteurs/Deutz/ENGINESDEUTZ912-913.pdf pages 2.00.15-2.00.20 - this is the mixed language workshop manual for 912/913 (german/english/french/spanish).

So no worries, repeating some of the steps can't harm but the workshop manual has all.

Regards,

Josef

 

[swd40]

I have chewed my way through the excellent and very informative translated articles and (because my injection-pump is a fresh professional rebuild) I don't want to start removing the pressure valve. This leaves only the canonical service-manual method aka. the high-pressure method requiring a 30bar/430psi hand pump (which I do not have!). I have upped the english content of the 23 steps of this method for reference (see links at bottom).

The image shows a plugged relief port #1, a ready-to-receive inlet port #2, and a drip-pipe #3. Sonce the pressurised inlet supply will be up to 435psi I think that plastic hose extension will have to be replaced.

There remain just a few questions that I need to confirm/clarify because I really don't want to mess this up:

The drip-pipe (orange) is really nothing other that the lower half of any injector-pipe?

Nothing is removed from the injection-pump #1 outlet port other than the (white) operational #1 injection pipe?

After having backed the crank about 90 degrees from compression TDC, what do I expect to see while pumping, nothing or a flow?

What do I expect to see as I reach the C-of-D point, do I see a last drop or a first drop just forming?

What do I expect to see as I veer the crank further PAST the C-of-D point?

Hi,

correct, with that high-pressure pump (I think kfptr said it is a 30 bar pump) you don't deinstall the valve inside the injection line outlet.

Deutz has some special injection line (step 7) that is just an elbow but that's just standard injection line.
In step 9 you need to pump diesel to deaeriate it. This works until you get to the 'Förderbeginn' (step 11: commencement of delivery, C-o-D). At that point the pump closes the infeed line to the injection pump. Thus the hand pump will not pump anything and turning the motor farther will have the injection pump working, letting it drip few diesel as the motor turns. In german it is 'Kurbelwelle langsam in Motordrehrichtung drehen bis der Kraftstoffluß in Tropfen übergeht' - in english that would be like 'turn the crankshaft slowly in turning direction until diesel flowing turns into drops only'. The english translation is a bit missing out the point that you can pump on the hand crank fine (diesel flowing) until you reach the C-o-D point (diesel not flowing any more from hand pump, turning the motor has the injection pump working with delivering the injected fuel)

Some explanation of what we see here: As long as we don't reach C-o-D the infeed of the pump is open into the injector element inside the pump. So if you apply some pressure (that 30 bar from the hand pump) it pushes diesel through the valve inside the outlet port to the injection line. Under normal condition (injection line attached to the injector as usual) that won't happen with low pressure from the lift pump (1 bar) and the attached injector (which opens at 250 bar). In normal operation that step is pushing out surplus diesel out of the injection element since we don't need a full injection element depending on the gas throttle setting. So as long as you're before C-o-D you can easily pump some diesel through the injection element. As you reach C-o-D the injection element inside the pump closes off the infeed on that element to compress that amount of diesel inside the injection element. Since that needs 250 bar to open up the injector in normal operation it can easily surpass that valve on the outlet. But it's only that tiny amount of diesel inside the injection element that can deliver diesel at this point, and it's also related to turning the engine further (say, deliver 1 drop every half degree or so). So that's when the diesel flow stops and you only get some drips.

Read the explanation from Ölhand linked above, I think that also has some more explanation on it. There's also some documentation from bosch how these injection pumps work, especially the injection element closing off from infeed as C-o-D is reached.

Regards,

Josef

 

[bad sector]

Hi,

these steps are in http://amoko.free.fr/Documentations/Moteurs/Deutz/ENGINESDEUTZ912-913.pdf pages 2.00.15-2.00.20 - this is the mixed language workshop manual for 912/913 (german/english/french/spanish).

So no worries, repeating some of the steps can't harm but the workshop manual has all.

Regards,

Josef

Yes, believe me I know that it's a quadrilingual manual; it took me two hours to make and upload those images

I just felt bad about flooding the post with large inline images

 

[bad sector]

Hi,

correct, with that high-pressure pump (I think kfptr said it is a 30 bar pump) you don't deinstall the valve inside the injection line outlet.

Deutz has some special injection line (step 7) that is just an elbow but that's just standard injection line.
In step 9 you need to pump diesel to deaeriate it. This works until you get to the 'Förderbeginn' (step 11: commencement of delivery, C-o-D). At that point the pump closes the infeed line to the injection pump. Thus the hand pump will not pump anything and turning the motor farther will have the injection pump working, letting it drip few diesel as the motor turns. In german it is 'Kurbelwelle langsam in Motordrehrichtung drehen bis der Kraftstoffluß in Tropfen übergeht' - in english that would be like 'turn the crankshaft slowly in turning direction until diesel flowing turns into drops only'. The english translation is a bit missing out the point that you can pump on the hand crank fine (diesel flowing) until you reach the C-o-D point (diesel not flowing any more from hand pump, turning the motor has the injection pump working with delivering the injected fuel)

Some explanation of what we see here: As long as we don't reach C-o-D the infeed of the pump is open into the injector element inside the pump. So if you apply some pressure (that 30 bar from the hand pump) it pushes diesel through the valve inside the outlet port to the injection line. Under normal condition (injection line attached to the injector as usual) that won't happen with low pressure from the lift pump (1 bar) and the attached injector (which opens at 250 bar). In normal operation that step is pushing out surplus diesel out of the injection element since we don't need a full injection element depending on the gas throttle setting. So as long as you're before C-o-D you can easily pump some diesel through the injection element. As you reach C-o-D the injection element inside the pump closes off the infeed on that element to compress that amount of diesel inside the injection element. Since that needs 250 bar to open up the injector in normal operation it can easily surpass that valve on the outlet. But it's only that tiny amount of diesel inside the injection element that can deliver diesel at this point, and it's also related to turning the engine further (say, deliver 1 drop every half degree or so). So that's when the diesel flow stops and you only get some drips.

Read the explanation from Ölhand linked above, I think that also has some more explanation on it. There's also some documentation from bosch how these injection pumps work, especially the injection element closing off from infeed as C-o-D is reached.

Regards,

Josef

Thank you very much! I decided to quote all of your appreciated reply so as to optimise its survival for others looking for this info. It's a mouthful and it'll take me a while to digest it but this is what I needed, as they say the devil is always in the details. Once I have it all figured out I'll make a video and put it on u-tube.

I'll be back with a few more questions maybe tomorrow.

 

[bad sector]

I received the hand-pump today and made an M14 banjo adapter for it. I think I have all I need to do this timing. In review the procedure should then resemble this:


Back off (CW from rear) about 90 degrees from compression TDC.

Begin turning the engine in normal direction of rotation (CCW from rear) to return to that compression TDC.

Normally the low-pressure feed pump would now be filling the cyl-1 injection plunger and nothing would flow out the injection pipe going to cyl-1.

But the hand-pump high pressure overrides the cyl-1 injection element relief and so fuel flows into the pump element AND also out the cyl-1 injection pipe.

Observing this flow tells us that in this sector of rotation the plunger is filling up.

Reaching the CoD point the fuel inlet that the hand-pump feeds is shut closed, and hand-pump fuel in no longer admitted through it i.e. the observed flow stops.

Now the already filled up cyl-1 injection plunger begins to compress the fuel it already holds (a few drops which it would normally send out as a squirt at very high pressure) but turning the engine slowly this will mean a total of some drops forming and falling away.

As the previous flow stops and the first one of these few drop BEGINS to form on the u-pipe open end, THAT is the marker for the beginning of delivery or CoD (Commencement of Delivery) point.

One could say that this point is half-way between the total cessation of flow and the beginning of the first drop but nailing that down would be impossible so it is the beginning of the actual formation of the first drop that is used for timing.

This point should be reached at 31 degrees before compression TDC.

I think it's very important to itemise action-and-observation steps because right from the beginning it is the validation of these that gives one confidence in the procedure.

 

[bad sector]

...done!

it's been quite an experienceand a learning curve thanks to all who chimed in on the topic. Without help from [B]Stihl_026[/B] &[B] swd40[/B] I would have been between a rock and a hard place which is all that the canonical 'manual' is good for. Here's a video I made, let whoever needs it make good use of it