air con causing flat spots

[Kirisute]

on my 2l allure
ive been trying to hunt down the cauyse of flats spots under heavy acceleration, round about 2800 thru 3100 rpm

tried EGR which seemed to help (but looking back on it it might be coincidence with the weather)

seems ive now nailed the issue...
ive been running with AUTO on the air con; so air con has been functioning pretty much always.
turning to ECO mode has removed the flat spots pretty much entirely.

Now i know aircon does effect performance but without another 2l to judge against im not sure if the clutch/pump of the aircon unit is causing the issue of if its pretty standard in its effects across most cars.

any insights?

[Capncol]

Can't say it makes much difference to our 1.6.

[Kirisute]

its really only present if you put your foot down! heavy acceleration from 2500 throuhg to just over 3000...then she picks up again....
im kind of guessing if you dont "drive it like you stole it" occasionally you might not tell anyway! LOL
which is why its not a big issue for me anyway...was just curious to try to get to the bottom of it.

[gazza82]

I take it there isn't a problem with the a/c off? On my Alfa a flat spot there wiuld suggest the MAF ( air-flow meter ) was failing. Never shows up on diag system though. To prove it we unplug the maf and see how it performs. Puts EML on temporarily until reconnected.