Causes of Fuel Cut beside boost leaks?

[twinturbozs]

Im getting FC when i romp on the throttle in the early rpms (3-4k). I tested my IC pipes and i have a very small leak inside the turbo itself. But the system can still hold pressure for at least 5 minutes losing about 2psi per minute. Doesnt seem like enough cause FC.

Are there any other reasons for FC besides a boost leak?

SP61GT
Lexus AFM/550's
MKIV fuel pump

Im starting wonder if i actually have 550's injectors installed. Since i bought them from another member years ago.

 

[MDCmotorsports]

Large turbos flow more air at less psi.

So if your ct was making 14psi with no fuel cut, your SP61 is now at around 10-11psi with fuel cut...

FIX THE LEAK.

(The leak may be causing the wastegate to stay shut)

 

[twinturbozs]

The leak is coming from within the turbo. Might be from the brass nipple to the wastegate line. i cant be sure, but its not coming from the pipes since i was able to spray them with soapy water without bubbles.

 

[MDCmotorsports]

Theres your answer.

The leak is causing the wastegate to stay shut.

 

[LordLo]

Mine does the same thing, on my ct26 it was hitting 15 psi fuel cut. Now with my t4 it hits fuel cut around 10 psi. I'm going maf as a fix, since maftpro is too expensive.

 

[twinturbozs]

Ok if thats the problem how do i go about fixing it? Ive tightened the fitting as much as possible without stripping it.

 

[GrimJack]

Pull it out and wrap the threads with teflon tape?

 

[MDCmotorsports]

Teflon tape or remove the compressor housing, drill a larger hole, and install a larger TAPERED brass fitting.

 

[twinturbozs]

I thought i read somewhere that teflon tape was not recommended on any fittings touching the turbo?