I am having my injector pressure adjusted how high should I go?

I am going to have my injectors cleaned and adjusted, the great news is they will set is at the pressure that I want. I am leaning towards 220bar on .184 injecotrs. I suspect that this should reduce my smoke by better atomizing the fuel. This of course will increase some of the loads on the timing belt but it will still be well below that of the auto TDI and just above stock pressures on the stock A4.

Since most of my driving is at 3,000 rpms on the highway the better atomizations should help redduce my soot output. Since I have deactivated the EGR (only off road of course ) the visible soot has decreased. I do suspect that I am due for a good cleaning and adjusting so when I have it done I will post all the before and after specs.

DB

This is on your A3? It'll be interesting to see what happens. I don't know if any mods were made to the injector pump for the A4 engines.

-mickey

Just out of curiosity, what price were you quoted for this job?

The A4 and A3 injection pumps are identical except for the pulley.

What determines the injection pressure si the break point that is set by shims in the injector(s). The higher the break point the higher the peak pressure spike thus better atomization.

I was quoted $6.00 each to dissasemble and clean my injectors (WHILE I WAIT!!!) for another $13.00 they wil put them on the test stand and check break pressure flow pattern and adjust to the pressure that I want. with prices like this it makes me want to go to my dealer just so I know what a good But F&#$in I'm missing

DB

and where are you having this done?

Gonna get this done so you can haul the Holset Turbo up to the 'Barn' in august?

I have a Bosch service center near me that is going to test out my injectors. I am going there today to let them tak a look to see if they have the shims for the TDI injectors.

I may not be bringing ALL my stuff to the barn the next time. I plan on kicking back and enjoying a nice day in the country. Then try to blow up the Holset!

DB

The shim inside the injector can be used to adjust pressure: increase in thickness of .05mm increases opening pressure by 5 bar / 72 psi.

SP thanks. I knew there was a pressure/thickness relationship. I am getting ready to head over there, they want me to bring the car in so they can check it out .

DB

Pistol Pete:

Can we gain anything by tinkering with the size of the "pulley" between the A-3's and A-4's?

Steve, you are not thinking.. if you adjust the size ie, diameter, of the pully on the IP, you are going to really screw up your injection timing!

Drive ON!