When i apply the throttle boost about 0.5 kg/cm2 till 4500 rpm then it drops to 0. But if i release and reapply the throttle at about
5000 rpm boost rises slow pass 0.5 up to 1 kg/cm2

Any help would be great thanks

 

What setup are you running and what are you using to measure the boost?

 

standard setup with HKS intake. the boost gauge is Greddy

 

sounds like youre having the same problem im having.
what mods are you running?

 

You either arent making 8 psi to make the second turbo come online or maybe you have a serious boost leak of some sort.Did this just all of a sudden started to happen? or has it gotten progressively worse?

 

Sounds like the charge control solenoid is malfunctioning or more likely, a vac line has come off this solenoid. See

http://www.k-rad.com/3genfaq

section 5.1.2.

--
j. stuart

 

the problem happened about 2-3 days after i fitted the HKS intake.

the second turbo comes on line if i release and reapply the throttle at about 5000rpm.

i checked the vacuum line but they are all attached.

Could the vacuum lines have same brakes in them that can not be seen and only open under boost???

 

there is a good thread in the archives about this boost issue and how to diagnose what broke. check it out. and search for secondary boost. been discussed many times. sounds like one of the hoses for the bov things split. i always forget the achronyms. or one of the vacuum lines got knocked off during your install.