Bucking - low rpm, warm. No second boost.
 

Hi all,

​​​​​​Finally got myself an FD couple days ago and I do love it, but I have two following issues:

1st Problem: Car runs fine until at op temp. Then when warm it will buck and miss and jerk about and be almost undriveable at low RPM.
Conditions: Anywhere under 3-3.5k, on light throttle. Soon as you get the throttle down enough, it boost up and flies. Similarly, as soon as you get the car above the mentioned RPM, it drives silky smooth. Idles a perfect 800rpm.

2nd Problem: Second turbo doesn't seem to exist - 1st turbo pulls like a train until 4.5k, and then it's a slow rise up the rev range like all boost is gone. I thought this might be an infamous vacuum solenoid but want the first problem fixed first.

Car specs: 92 JDM Type R, only mods are decat and catback. Engine rebuilt 13k miles ago, starts instantly hot and cold.

Also, i have searched the whole of the interwebs and have read about grounding and TPS and stuff but I'm new to this car, it seems there may be many variables for the bucking. The '3k hesitation' everyone talks about implies that people still drive their card but it hesitates... Mine is undriveable at low RPM once warm, unless you're getting hard on boost everywhere.

Yesterday I found out that the previous owners installed the decat and exhaust without having an ECU/Remap done, so now we don't want to drive it for fear of detonation.

I dare you to say 'Welcome to rotary ownership' :)