VCDS help

[Adman]

Hope someone can help. Need advice on using VCDS.

A little background...
I have owned the my 2006 2.0 tdi 170 A4 for nearly 2 years. Ever since i have had it it has run quite badly from cold on idle. 3 months after owning, first injector went. Then nothing until about 4000 miles ago when the glow plug light came on and the car konked out. To my amazement car started and that was 4000 mile ago. Took it to a garage at the time who scanned it (I didn't get the codes) but they said it was to do with injector one - short to plus. Since then the car has run but really rough on idle (much worse than before) when cold and hesitates around 1800rpm.

I am adamant that the reason for the rough idle is to with the injectors. I have just bought a copy of VCDS and want to know if there is a way of checking what fueling is going into each injector?

Hopefully someone out there can help.

Thanks in advance.

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[martin1810]

Block 013 can be logged at idle or any engine speed. It doesn’t have to be an acceleration log.

013. 1 Injection Quantity, Deviation Cyl. 1
013. 2 Injection Quantity, Deviation Cyl. 2
013. 3 Injection Quantity, Deviation Cyl. 3
013. 4 Injection Quantity, Deviation Cyl. 4

A graph of these results can be done against the time stamp column but it will look a mess.
It is simpler to average the results for each injector and look for any really odd figures.
All 4 injectors should have similar figures as close to zero as possible.
E.g.

13, 1, Injection Quantity, Deviation Cyl. 1. -0.28 mg/str
13, 2, Injection Quantity, Deviation Cyl. 2. -0.49 mg/str
13, 3, Injection Quantity, Deviation Cyl. 3. 0.56 mg/str
13, 4, Injection Quantity, Deviation Cyl. 4. 0.21 mg/str

If one injector is well out of specification compared to the others it could be faulty or it could be a faulty cam lobe.
If all figures are all over the place it suggests worn camshafts.
It is hard to tell if an injector oddity is due to an injector fault or a camshaft fault.
Apparent multiple injector faults are usually worn camshafts.

[Adman]

Thanks for that,

had a bit of a play this afty and found the following-

At Idle
18:03:10 Group 013
-0.41 mg/str Inj. Quantity
0.49 mg/str Inj. Quantity
-1.00 mg/str Inj. Quantity
0.93 mg/str Inj. Quantity

At around 1300 rpm
18:05:03 Group 013
-0.85 mg/str Inj. Quantity
-0.36 mg/str Inj. Quantity
-0.79 mg/str Inj. Quantity
2.01 mg/str Inj. Quantity

Engine is quite lumpy at idle, when at 1500 rpm its shake you teeth out!

As i mentioned before, there was a fault with injector 1 but injector 4 has been replaced already. Does that suggest the rest toast?!!

Thanks

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[Adman]

Have now posted this on B7 forum

https://www.vwaudiforum.co.uk/forum/s...946#post649946

Thanks

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[martin1810]

Your figures are within VW spec. These injectors suffer faulty electronics but usually they play up for a little time and then the ecu switches off. Then the car won't start.
Have a look at the fuel filter to check it isn't full of oil. (black). One thing that can cause your symptoms is damaged seals on the injectors. These can be damaged when an injector is fitted.

[Adman]

Thanks Martin
Its had the injector seals done twice to no avail unfortunately. I've got to do a full service soon, so i'll check the filter for oil then.

Cheers