vagcom to detect misfire?

[missmouse]

is there some way ( & if so how?) to use vagcom to detect where a misfire is coming from on my 2000 B5 RS4 while under high boost? It runs great on lower boost but when it goes over about 16psi I get a definite misfire. this has gradualy got worse at first it was only over 21psi but now its down to anything over 16.
No fault codes shown, plugs look ok ( not very old either)
If nobody knows this, can you point me to anyone who might?
Cant understand the secrecy behind vagcom!
( genuine paid for version!)

[zollaf]

there is no secret. a diagnostic computer detects a misfire by sensing the rpm. a slight slow down at any point is flagged up as a misfire, hence why at higher rpm it usually can't pick anything up. it will also pick up a change in resistance in a coil pack. so by there being no fault code and it only happening at higher boost, it is telling you that it might be an idea to change the spark plugs as one of them may be faulty.

[missmouse]

thanks for that Zolaf, but is there no way in which vagcom can detect which cylinder is misfiring? I have alread had all the plugs out & they all look a good colour & also they are only about 2500 miles old!
I used to be able to access a yahoo group where rosstech staff & others who know how vagcom works would give advice on such things but I can no longer get in - maybe it has closed?

[zollaf]

how can it detect a high rpm misfire. its only a computer. has this misfire started in the last 2500 miles or was it there before the plugs were changed. what make plugs ?

[Doctle Odd]

You can use VCDS to get live data but only data from the various sensors and modules in the car. It won't pick up a dodgy plug or a dirty filter etc

[missmouse]

so it cant detect live data while im driving? I had hoped it might be able to show each cylinders performance at any specific speed?
many RR computers can do this thus showing a fault ( maybe not exactly what the fault is granted) so you know where to start!

[Doctle Odd]

See my previous post!

[zollaf]

see mine as well ??

[missmouse]

ok, so vagcom cant do this? Thanks

[Doctle Odd]

you can use vcds to gather live data.