2.5 tdi V6

[rizla3066]

Ok i need some info to resolve some issues i have.

2004 A4 2.5 TDI V6 (163bhp) - Multitronic

I have had this car a few months now and all semed good at first but i am starting to notice a few things. The car seems to idle rough sometimes. I took it in for a service a few weeks ago and the mechanic told me there was a misfire as he could feel it knock the car. i had noticed it before but never thought anything of it. It will only happen when the car is warm and the cold start has cut off so it idles a a little slower.

I have scanned the car with VCDS and no error codes are shown. I also had a look TDI timing by going into basic settings but there is no TDI graph cause i am using VCDS lite. The only other thing i did notice was in group 13 and 14 it shows injected quanitity for each cylinder but it is not showing cylinder 2??????? Surely this cant be correct??? In VCDS i have

Group 13 - Cylinder 1 deviation, Cylinder 3 deviation

Group 14 - Cylinder 4 deviation, Cylinder 5 deviation, Cylinder 6 deviation

So that is my first problem question

My second question is, while trying to isolate this rough idle and misfire i did a injector leak off test to see if any was blocked but i have run into another issue, from what i remember you should have some diesel returning to the pump even if the injector is ok, however i done the test for over 10 minutes at idle and had virutualy no return atall for any of the injectors a few mm was the worst????

 

[adamss24]

What are the values of the injectors ? There is no cyl2 as the car takes reference from the needle sensor on the 3rd injector- a bit weird but there must be reason the VAG engineers done it that way ! The return hoses/leak off pipes will leak a tiny amount of fuel on idle, without seeing how much they leak i would not condemn them as bad...

 

[rizla3066]

Hi thanks for the reply, afetr a while i started to think the other cylinders where deviations from the first reading which i think is in group 15?

Anyway i have the readings you asked for and a few more if needed lol

From a cold (ish) start

Group 13 - Injection quantity deviation 1
Cylinder 1 = 0.47 mg/str
Cylinder 3 = -0.31 mg/str

Group 14 - Injection quantity deviation 2
Cylinder 4 = -0.16 mg/str
Cylinder 5 = -1.33 mg/str
Cylinder 4 = -0.24 mg/str

Engine up to temp

Group 13 - Injection quantity deviation 1
Cylinder 1 = 0.00 mg/str
Cylinder 3 = -0.16 mg/str

Group 14 - Injection quantity deviation 2
Cylinder 4 = -0.39 mg/str
Cylinder 5 = -2.12 mg/str
Cylinder 4 = -0.39 mg/str

 

[rizla3066]

Anyone else with advice on this? Do the values above look correct for said car?

 

[adamss24]

Cyl. 5 is off but i would get all 6 refurbed... If you need a good working set then let me know...

 

[rizla3066]

Thanks, what do want for the set you have?

Also another question, i can see some injector sets on fleebay and one injector has a wire, whats that about because looking a mine there are no wires coming from any of the injectors?

 

[adamss24]

The injector nr3 as you look at the engine/driver side towards the bulkhead it has a lead...