hi i need some help i own a classic 1998 wrx sti ver 5 import
today it was driving fine ...........
i was told to change the manual boost controller as there crap!!!!! so i bought a 2nd hand factory fit unit to put back on after doing this took it for a drive and it was jumping as it hit boost
so thought it was faulty
changed it back to manual boost controller and its still doing it .....
wtf is going on
can anyone help me ?

 

STi Version 4 = Sep 97 to Aug 98

STi Version 5 = Sep 98 to Aug 99

Which is it, just to square that away? Is the coilpack in the centre, or on the passenger side of the inlet manifold?

A take it you mean you junked the MBC and refitted the OEM 2-port boost solenoid?

Have you connected it up correctly? Is the restrictor pill in the short piece of vac pipe between the compressor nipple outlet and the T-piece, as well?

 

sti ver 5 98 / 99 coil pack in middle and 3 port boost solenoid and yes still got the pill fitted !!! could do with some pics of where all the pipes go so i could check em all !!!!

 

Coilpack should be off centre to the passenger side on the v5/v6!

2 port is OEM fit on the MY99/00 v5/v6 cars, but a 3-port can be fitted for better boost control for sure.

OEM 2port BCS:-




Early 3port BCS:-

 

mine looks tottally diffrent from both of these !! but pretty sure that its piped right now !! still got engine check light on !!!!! and jumping !

 

You prob have an after market 3-port such as a Perrin or Apexi item.

After market ones usually have their ports labelled:-

"NO" = normally open
This connection goes to the compressor cover's outlet nipple.

"COM" = common
This connection goes to the wastegate actuator.

"NC" = normally closed
This connection is left VTA... Or back to the air intake, upstream of the turbo i.e. the filter side, not the IC side.
(If left VTA, make sure the appropriate unused vac return port on the air intake is bunged off.)

 

Also if you remove the standard boost control solenoid, it will bring up a CEL

 

do anyone have any pics or illustrations of where all these pipes are meant to go on the engine and sensors etc reckon 1 of the kids may of changed a few around grrrrrrrr