Help needed diagnosing lumpy power delivery

[SideshowBob]

Hi all

I've got a strange problem with my Mk1 Octavia vRS, in that I get uneven power on medium throttle openings. On full throttle it seems fine, it idles nicely and is smooth on a constant throttle. But if I open the throttle halfway, say around 7-10psi on the gauge, the power is lumpy and uneven. It's as if the boost is wavering all over the place but the recently-added boost gauge tells me that the boost is staying constant. There isn't any 'kicking' that I'd associate with a duff coil pack, it's more subtle than that.

My car has a stage 1 remap (Performance Torque), forge 007p and a PiperX dry filter, that's about it really.

I managed to get some VAG-COM logs done (thanks mikeholroyd ) and I've attached the results. I'm not sure the sampling rate is enough to show up any problems so we might have to figure out why that happened and do some more runs. However does anything look amiss to anyone on the logs that we did already?

We logged blocks 002, 115 and 118.

Log 1

Log 2

Log 3

Any help appreciated as always.

Edited 4 November, 2010 by SideshowBob

[Guest westallc]

you need to log it in 3rd or 4th from 1500rpm to as far as you dare go as the logs you have done dont show much

the only thing i wil say its the g/s reading are very low

try unplugging the maf and going for a drive

[SideshowBob]

Ok will give that a try. If the maf is goosed, what happens when I unplug it?

[Lew_VRS]

Ok will give that a try. If the maf is goosed, what happens when I unplug it?

The car will drive a bit better, think it puts a nominal value through it for AFR mixture

[SideshowBob]

Ok I disconnected the maf for a few miles tonight. Didn't seem to drive any different really, the lumpy delivery problem was still there but it didn't run rougher or anything. Might have to try it again just to be sure.

Does that mean the maf is ok or is it knackered?