Ibiza 1.8t fr 04 massive hesitation around 4000 rpm

[Vrchris]

Hi all.
Just acquired a Ibiza fr 1.8t on a 04 plate.
Car has covered 113,278 miles and I have no service history for it. And currently has a inspection light on so due service.

Main issue is that when accelerating rpm hits around 4000 rpm and you get thrown into windscreen. There are no dtc showing with our snap on solus and today purchased vcds. And no codes showing on there. Replaced airflow meter. Battery. Plugs with pfr6q items. All 4 coil packs with ngk u5003

Unfortunatly we don't really specialise in vag cars been a JDM specialist. But am getting to a point that I'm more guessing than fault finding. Iat looks normal. Coolant temp reads around 90 when idle and at temp. So going to rule them out. Think car has been mapped. Has a CAI and milltek cat back system.

Vagcom new to us but getting used to it. So if anyone can think of any tests I'm all ears. ( or eyes. Lol).

My next step is to check engine timing make sure belt has not stretched or jumped a tooth. Will post up results.

Can't see or hear any boost leaks. Checked everything I can find. Will start replacing vac pipes soon see if I get lucky. But nothing visable wrong here.

Thinking fuel pump maybe as its only in the higher rpm that there's a issue.
Do these have a ignition amplifier/control unit as the golfs do.

Sorry for the war and peace essay just trying to fill you in with the facts.
Cheers
Chris.

 

[Vrchris]

Forgot to say also has a forge recirculating valve fitted.
Cheers.

 

[Lowry020505]

Could be vac lines split, try the n249 bypass, theres plenty of guides on here how to do it,
It's proberly already been done with the hardware it's got tho

 

[Vrchris]

Bypass

This actually has not Been done. But has now.
Have got a little more info on the fault, running very lean at 17.9-19;1 on boost.
So no wondering what can cause this.
Replaced fuel pressure reg and filter.

Guessing only leaves primary lambda and fuel pump to be at fault. Possibly injectors.

 

[Lowry020505]

Have you checked the pvc hoses, they tend to go under the intake manifold, I fitted an oil catch tank on mine and done away with all,

 

[Vrchris]

Have you checked the pvc hoses, they tend to go under the intake manifold, I fitted an oil catch tank on mine and done away with all,

fault was fuel pump.. although whats good to get rid of on these engines bypassed vac box and piped fuel reg and forge valve to inlet. wondering about secondary air pump.

 

[Lowry020505]

You done the n249 bypass then,, notice any difference?

 

[Vrchris]

Yea done it although as never really driven car before doing this unable to tell really. It's all still there so might plumb it back in. Just to see if there's a noticeable difference. Did notice today a flat spot/ slight hesitation around 3500 rpm. Any ideas?

 

[Vrchris]

Just aquired a t28 turbo so will be fabricating a manifold for that. And a large front mount. Hopefully get rid of the issues before fitting them. All the unnessaserry crap too. Lol. Secondary air is next along with intercooler fitting.