Flat Spot/Hesitation between 3000 and 4000 RPM Valver

[Shizzle]

Flat Spot/Hesitation between 3000 and 4000 RPM a friend of mine is having these troubles on his GTI 16V.
I have not come across these troubles on my golf and have no clue can any one help.

Starts up 1st time no idle issues no running issues before 3000 and after 4000rpm it drives fine with no faults.
But loses all power at 3000 rpm until around 4000rpm.

[Len]

ECU relay

[Shizzle]

Thank you i'll let him know  .

[Len]

Thats first port of call as its and easy and cheap fix.
If that doesnt fix it then you had best read up on it here as there can be many other causes, but thats always been my favourite for that fault

[tweed]

Coil is good for that too

[GOLF-MK3-GTI]

Maf Sensor.

[Len]

He said no faults so assume he has checked for codes which is why I said ECU relay as that doesnt show up on a code reader.

[Shizzle]

He Has ordered that ECU Relay £12 il let you know how it goes MAF?

[bigberty101]

you don't have a maf on valvers ( mass air flow sensor near airbox on 8v) but you do have a map sensor in the ecu run by a vacuum line off the back of the inlet