Mr2 Turbo Overboosting Problem

[A-j-B]

Here is one for you guys. I own an imported Rev.1 mr2 turbo with the following mods: K&N cone filter, Blitz Nur SpecR with decat pipe and an HKS FCD. There are no other mods and the FCD is set at setting 7. The problem I have is that on occasions, mainly above 4k revs, i'm still hitting fuel cut. At the mo I only have the standard boost gauge which never goes over 3/4 boost and i'm getting a code 34 (overboost) and a code 35 (boost sensor). I'm wondering if my FCD is not working properly. At setting 7 the fuel cut should be around 17-18psi, but could I be boosting past this with the mods that I have hence the fuel cut? Even at setting 5 i'm hitting the fuel cut! This cannot be right! Also would the FCD cause the MAP sensor error or is that knackered too? I've even thought of taking off the FCD. Any ideas would be a big help. Hitting fuel cut when trying to overtake someone is never a good thing!

[dawesy]

first thing is get a proper boost guage. the std one is more of a yes you have boost, no you dont indicator.

if you have a 3" decat and exhaust system it can cause boost creep due to the poor flow of the CT series turbo's wastegate.

the rev 1 dosnt have a map sensor it is AFM it does have a turbo pressure sensor and it possible its this thats faulty.

first you need to find what boost the fuel cut is occuring.

[MDavid]

I have overboost with fuel cut off. The aftermarket gauge reads about 0.6 BAR when it happens. It is a 1990 Rev1. What should I look for and where?