Some thoughts on this.
Caveats. Due to the nature of the adaptive ECU I've thought I've found solutions before but then they return, however, so far so good. As you can see I run the (when standard) 180 lump. I'm not sure of all the various SEAT versions, sorry. My car has always been a dog when clock cold but 5 minutes and it's fine, I'm talking about when the car is run in here. It's a Skoda
Now, does this sound familiar? For example I'm accelerating, I'm in third, I'm doing about 40. The traffic suddenly slows and I drop down to second, the revs drop to below the point the turbo is kicking in, say 12-1500rpm, as I let the clutch back out and try to pick up speed again the car stutters and then picks up. Sometimes the stutter is more pronounced and is a genuine, full on flat spot. It picks up for a second then seems to flatten out, then goes again. All this makes town driving a bit of a chore but you can drive around the
problem by generally using more revs. But that isn't a solution. There is something wrong.
I've had all the above for about 18 months and it was driving me mad. As it turned out I actually had two problems.
Firstly, my Forge DV was FURBAR. We (me and Kev at JBS) had never really considered the DV because, well, it was Forge. As it turned out the spring was yellow (stronger) than the standard green and as I spend most of my time pootling around town the delivery was a little harsh. Also, somehow, the DV was full of general grot and metal filings from the top of the spring where it was rubbing on the housing. Changing the DV (we didn't have a maintenance kit to hand) transformed the power delivery. It was like driving another car. The full on flat spots had now gone.
Secondly, even after changing the DV, I noticed the stutter was creeping back. The car always seemed to improve after doing a throttle body alignment so I guessed the
problem must be related. So back to JBS to have the throttle body cleaned. It looked simple enough but I know my limits
Basically the unit comes off, a liberal spray with carb cleaner and a wipe and then back on. Kev realigned everything again and so far the car has been as good as gold.
If any of this does sound familiar forget your MAF, N75, coilpacks etc etc. I've changed them all and only changing (or servicing) the DV and cleaning the throttle body have made a difference.
Sorry for the long post