Boost issue

[BillalA]

Hey guys, so on my Mk5 GTI stage 1 recently have changed the oil pick up pipe, MAP sensor and upgraded to R8 coil packs. While driving (on the motorway) I accelerate hard to which the car responds but then it loses boost completely. After that it drives literally with no power. However if I turn my car on and off I have boost again until it the process of losing boost repeats.

Not sure if this affects it but since the change my cars juddering/misfiring Upto 2k revs CEL light flashes and then goes off

Does anyone know what the issue could be or what I need to replace/check?

Any advice/help will be greatly appreciated thank you.

[breeze]

Could it be a fuel cut?

Mileage and how old is the fuel pump cam follower?

Ideally you need to read codes with a VW specific reader (not a generic one). Not that expensive on Amazon.

[BillalA]

It’s on 88k miles I replaced the fuel pump cam follower around 82k miles along with the pcv and the dv

There’s no engine codes apart from overboost and also cylinder 1 misfire. Cyclometer 1 misfire stops as soon as I disconnect the MAF sensor

[ROH ECHT]

Did you replace the MAP sensor because it had the over-boost code?
Did you replace it with; 038 906 051 D?

What data scan tool are you using?
Can you view live fuel pressure data? If so, what are both high and low pressures at idle when it is warmed? Also, what is the LPFP's duty cycle-%?
Have you done a full scan? Sometimes something like the throttle pedal assembly can cause issues very similar to yours.

[BillalA]

Appreciate your response buddy,

I changed it because a guy local to me who is deeply into his MK5 GTI told me to after he drive my car he said it needs the MAP sensor changing. I replaced it with a MAP sensor from Eurocarparts (Bosch)

 I’m using the local garages Snap-on tool, unfortunately cannot see any of the data you said. Is there a diagnostics tools of some sort that I could buy?

[ROH ECHT]

Appreciate your response buddy,

I changed it because a guy local to me told me to after he drive my car he said it needs the MAP sensor changing.
 I’m using the local garages Snap-on tool, unfortunately cannot see any of the data you said. Is there a diagnostics tools of some sort that I could buy?

I think confirming the WG is opening and the runner-flaps too are opening, would be my first things to want to confirm; regarding the over-boost. It's ECU is likely shutting it down in order to protect the engine.

I believe, for a diagnostic tool, many use the OBD11 for its lower cost than Ross-Tech's VCDS cable ($199 usd). But I use VCDS and am not certain of all OBD11 can do for you.

It seems to have more than one issue, as I doubt the #1 cylinder misfire is related to the over-boost. The misfire may just be ignition related, or intake-valve buildup, but is more likely an injector not working at its peak.