Quick VCDS Injection Quantity Deviation Question

[SDHA4SLine]

Had a fellow member plug in vcds to do a little investigation on my car. We noticed that values between injector 1 & 4 look like they're compensating for one another. I dont know what sort of values should be ringing alarm bells and what are normal so... are these values anything to worry about or are they perfectly fine?

Thanks
Steve

 

[carlcall]

Sorry Steve I can't answer this for you but was that from cold or warm and I may plug my VCDS in later to see what my values are.

 

[Charlie Farley]

Errrrrrrrrrr... thats not good steve, looks like a vist to the garage again and flashing the plastic again.





No only joking steve, cant say i can help you either , but, i'm sure an expert will be along very soon..... probably just a minor tweek needed.

 

[Charlie Farley]

or this may help you steve.

The deviation is the correction that the ECU makes to maintain smooth idle. SO if the correction is too big that points to the injectors having troubles. The first thing I would do is to run a Diesel Purge through and try to clean things up. If that shows no improvement, then it's time to think about having the injectors rebuilt.

 

[Charlie Farley]

found this too.

Normal. Only start worrying when they go past -/+ 1.2 once warm.

Big deviations can point to bad camshaft, bad lifters, bad valves, bad compression or bad injector(s)

 

[Charlie Farley]

or, found this steve,
http://www.vwaudiforum.co.uk/forum/showthread.php/56547-Random-Injection-Quantities

there you go, more info than you can shake a stick at, hope it helps abit.

 

[SDHA4SLine]

cheers rob, looks like im good then, well in on the tolerance

 

[Charlie Farley]

your welcome chap, and have a good day now.

 

[desertstorm]

As already said those reading are actually very good. If you total them up they should come to close to zero.
Most cars I have seen tend to be more in the 0.3 to 0.6 region which is still fine.

 

[guyzza75]

My b7 2.0tdi BLB was showing number 3 cylinder out and had bad idling. It turned out to be the injector lash needed sorting. Runs smooth now ..the clearance between the injector and the rocker was too much..