GTiR acceleration problem after aprox. 4500rpm

[jagy]

Hi everyone! Im having a "little" problem with my GTiR, can anyone help me or point me what to look after?

Im having trouble with my GTi-R over aprox. 4500rpm - until this rpm, it runs ok, idle ok but then it will totally lost a breath and I can feel little shuttering all the way to redline and acceleration is like non-turbo GTi. Ive checked all air hoses and all seems well. Also installed aftermarket boost gauge (as my OEM one doesnt work) and its shows 10psi (0.7bar) from 3500rpm to redline. Ive changed plugs, rotor/cap, bov with no luck. Car is 100% stock, no mods.

Ive been told that it may be the stock fuel pump as they can worn out. What do you think? Thanks for help and input.

 

[The Doc]

Stock fuel pump, ign timing could be wrong, and more...have you done a fault code check? Have you set the ign timing? Have you had work done on the engine so the cam timing could be out?

 

[Fast Guy]

Is your det sensor playing up? Have you tried a new fuel filter?
Check the voltage at the fuel pump.

 

[jagy]

Yes, im getting 34 (knock sensor) fault code. Didnt touched timing with timing gun yet, but distributor is on stock position. Engine is stock, no mods to timing chain. Fuel filter has been changed too.

I will try fuel pump voltage...

 

[grim_d]

Change your knock sensor.

If fuel pump is standard its a good idea to uprate pump and wiring anyway.

 

[PobodY]

Change your knock sensor.

This.

Even fiddling with the wiring harness might be enough if the problem is a loose connection rather than a faulty sensor. - That worked for me, but I changed the sensor when the inlet manifold was off since it's such a pain otherwise.

 

[grim_d]

Its possible to check the resistance of the knock sensor to give an indication if its faulty or not, but if you have it out you might as well put a new one in.

Depends on your engine bay configuration but its not bad to change really, unless your Y bracket is still in...

 

[jagy]

Update:

Knock sensor fault doesnt appear anymore after I cleared fault codes. Doesnt seem like a problem to me, probably fault from long time before someone played with it.

Pump - ground seems ok, power is aprox. 12V - like battery. But when I contact battery straight to pump, cars seems like to run a little bit better, with no hesiation in powerband. But still, car feels slow like someone catch my rear end over 4000rpm. Here is datalog (max. values) from my EcuTalk Display:

Inj duty cycle 88% - seems damn high to me?
Timing 50° - ???

Any thoughts?

 

[geoff pine]

Your battery readings should be more like 14 .3 volts with the engine running .

 

[dev singh]

Have you checked or cleaned the MAF sensor