[sambeeb]

Hi,

I have a vw polo gti 9N3 with the audi 1.8T 20v turbo. It runs 1.4bar max, and a 0.4 "A" post intercooler/pre throttle body boost triggered (@0.85bar)nozzle.
I have been running generic flash tunes in my car but have facility to make changes to global timing changes across the timing map. In the past when setting up the water injection I would increase timing bit by bit until I could see timing pull generated by the knock sensors. I would stop there with my timing adjustments and then I would only continue on from there with the water injection active.
I recently changed to an updated flash tune and have tried to set up my timing in the same way. However I'm finding that when I run the water injection, the timing pull observed is actually increasing!
I have removed, cleaned and air tested the nozzle aok. I have moved the trigger point up from 0.85 bar to over 1 bar thinking that quenching might be at play and lower in case I didn't have enough early enough. I have gone slightly higher and lower around that critical timing point. This tune doesn't make more power than the last ie I'm not under watered compared to the last tune. However when I run with water injection I get slightly more timing pull!
My guess is that this tune is not fuel limited (its at 0.83'ish lambda) and so its going to be very hard to get any benefit from the water when I can't adjust fuel, but I'm struggling to understand what conditions would be at play for water injection to be not only not getting rid of the timing pull but enhancing it? any ideas

thanks
sam