2G Breaking up above 4000rpm LOW BOOST

[pointblank9957]

okay i'm here on behalf of my friend, he is having an odd problem with his 2g.

You must be logged in to view this image or video.

He'll floor it at 3000rpm, it won't build much boost and starts breaking up above 4000rpm on 6psi.
He's Done:
BLT- fixed SEVERAL leaks
Replaced Power Transistor
Replaced Plugs (NGK) and gapped to .028
Replaced Plasug wires
replaced coils
deleted all the vacuum lines that are not needed
tried a different ecu
replaced fpr
tried different stock injectors
replaced fuel filter

we're all at a loss of thought of what's wrong with it. NO CEL.

 

[wolf alchemy]

My guess would be he'll need to rebuild the turbo. I know that happened to my and thing was. Some thin metal was slowing my compressor.

 

[crimsondragon]

Tried a different MAF? It sounds like a boost leak though. What kind of exhaust system does he have? Give a full mod list.

 

[pointblank9957]

Tried a different MAF? It sounds like a boost leak though. What kind of exhaust system does he have? Give a full mod list.

no boost leaks and tried different maf.

Vacuum delete, short route fmic, greddy type fv bov, apexi 3" turbo back exhaust system, td06 20g, Turbonetiks T3 cast iron manifold. Maybe a walbro 255 not sure. , stock injectors

 

[crimsondragon]

Does he have an aftermarket adjustable regulator to go with that Walbro? Is that a true Apexi exhaust or knockoff?

 

[pointblank9957]

Does he have an aftermarket adjustable regulator to go with that Walbro? Is that a true Apexi exhaust or knockoff?

no idea, he said it might be a 190, and i'm assuming real but it should make no difference

 

[crimsondragon]

It does make a difference. Some cheap exhaust use a cheap flex Efron that can collapse and restrict exhaust flow. Just one of the things to check. Check and see if he's running an AFpR cause it's a 255, he'll overrun the stock regulator. Id start there.

 

[bryanwheat]

How much pressure was used for the boost leak test?