Slight hesitation

[The Spanish]

After all my upgrades and everything is almost new I find this problem, is very soft but it worries me.

Let me try to explain:
When I am accelerating and I give it 90% throttle car just flies off. 2 Bar max bosst and goes down to around 1.5 bar slowly.

If instead of 90% I go WOT I see some hesitation, car does not pull as fast, problem is this does not happen everytime.

I am about to change the fuel filter as it have been there for a while and the only thing I can think of is my coils are dying or maybe a WG problem. Car was full samcoed and restored recently, still will try to perform a leak test.

Thanks for your help in advance

[91_S2]

When I upgraded from one MRC chip to a better one, I had some heisitation at a certain rpm. Very repeatable. Since it wasn't there in the old chip, I thought it might be the new one has a fault.

But the heisitation is now gone without any changes to the car. I am wondering if the ECU just had to learn the new parameters or something like that.

[iain1067]

knock sensor cutting in maybe??? i am sure that the ecu does also learn a bit too, as it must if you change from one grade of fuel to another,

[The Spanish]

I always use 98 but I will put 98 + ocatane booster to see if I have improvements.

Thanks
Any other ideas?