11 mm 107j pump

Hello there,

Does anybody know how can be increased the pressure in the injection pump without being dismantled off the car? You have the link with some logs and it seems that injection pump is not keeping injection time. I was advised to increase the pressure in the pump.

https://www.dropbox.com/sh/4a5pmxq3tclidcr/AABWis16p6jdaI771_dpx4SHa?dl=0

Thanks!

Does your car have an auxiliary (electric) fuel pump in the tank? Our USA ALHs did not, and it was an easy way to add pressure to the pump, by adding one from the PD engine cars.

And the logs look perfectly acceptable to me, from what VCDS logs, there isn't much of a way to tell that there's anything wrong.

He doesn't have an auxiliary pump for now. The tuner says that the dinamic timming (from channel 4 in VCDS) doesn't follow the requested values in high rpm due to low internal pressure in the pump. Is lower with 2-3 degrees wich is something.
Is this a classic sign for the need of the lift pump? Is the pump starving?

We know that the logs are ok in rough line but is just a test remap, and for a fine tunning the pressure must be increased . There is more room to improve the figures.

PS: I know the details because I helped the owner with the HW modes and talked with the tuner.

Ok I see, as in LOG-01-004-xxx-xxx.CSV

Well hello Mr. Razvan, now we have both here.
(I thought you were the tuner? "Soft by Albulescu Razvan & EDC tuning")



I don't think I need to ask, but will anyways... the pump timing is correct?

I will attempt sometime to log my timing (just for comparison), although I am not fueling as much as you, with only a 10mm pump.

Hopefully some others can chime in as well.

I had the exact same problem - the pump can't maintain internal pressure with the increased fuel flow from stock so the timing rattles around all over the place and it shudders under power. Its simple to fix with a punch and a hammer and you can do it on the car If you have a vernier caliper that helps too.

In the pic below you can see the case pressure regulating valve painted red in the top left of the pump:



There is a recess in the top of the valve - usually there is some paint in it, and lots of crud & dirt. At the bottom of the recess is a steel plug which sits on top of the spring and piston. Clean the recess out and then find a centre punch which will fit in the hole and touch the plug.



What you need to do is push the plug further down in to the case valve. This will increase the force on the spring and piston and hence increase case pressure. I measured the depth of the plug on mine and then tapped it with the hammer & punch until I moved it 0.5mm. Took it for a drive, it was much improved, so hit it again and got another 0.2mm and the shudder was gone & timing solid.

Best to do it in small increments since otherwise you have to take it out of the pump to back it off, and too much case pressure will cause leaks.

Hth

Wow. Thanks for the great reply Mikkijayne. That's why I love this forum. A lot of people willing to share their priceless knowledge. I will recommend Bogdan (bios83bog) to go to Bosch and ask about the pressure increase. I'm not sure they know what to do )))

I didn't know that there is a steel plug there. I was thinking that there are some shimes inside with different sizes like on injectors body.

Enabled, I just intermediate the talking between Bogdan and the tuner from EDCtuning.pl . A great guy, by the way. He tuned my B5 AFN and then the current B6 AVF.

arazvan2002 said:

Enabled, I just intermediate the talking between Bogdan and the tuner from EDCtuning.pl . A great guy, by the way. He tuned my B5 AFN and then the current B6 AVF.

Click to expand...

I'm just giving you a hard time, a tease.

Besides, any more Romanians here and we can all switch to Romanian. Plot twist .

Hi, thanks for all guys! At the end we are tdi lovers!

So I just adjusted my 11mm as I was getting part throttle shudder at 1800-2000rpm
I tapped lightly, getting firmer, but the plug didn't move.
I then gave it a sharp couple of taps and its moved 1.5mm!!
So 5mm on the vernier is now 6.5mm

Taken it for a drive, no change to the shudder and no leaks....

I was really hoping this would have fixed the shudder

So have I gone too far? I assume too high a pressure wouldn't cause shudder to come back.

So I now need to log timing to see if it's keeping up?
On the other hand, do I need to go further?
I assume I now need to measure the current idle pressure?

You must measure the case pressure 11 bar @ 2000 rpm is fine.

Many thanks, is there a how to on this please?
What's the standard pressure?

Behind the pump at engine side there is a m8 bolt threads are m8x1 mm .
Remove bolt insert a bolt with banjo where you can put a tube on it then a glycerine gauge from 0-15 bar.

Hi mk1-83

All the threads ive seen on setting case pressures say the pump speed is 2000rpm at 11bar, so engine speed would be 4000rpm....

Can you confirm?

Engine speed 2000rpm and 11bar.

That's effectively 160 psi for us non-metric folk.