Pretty bad problems with my project...

[KwS]

right-e-oh... here we go again. im finally at the end of my tether, i need to know whats going on.

I have a V2 STi engine in my 92 Legacy GT. Been converted to manual, had the auto trans comp removed, inhibitor switch set to neutral. Currently running V2 STi ECU with Gizzmo chip (slightly more agressive tune and no cuts), but have tried with nonsti wrx ecu.

Basically, whats happening is if i have the IAC connector plugged in, the engine idles fine, but will drop to almost stalling and then jump upto about 2000rpm, ease back down... stay stable for a few secs and then drop again. If i try and accelerate with the IAC plugged in, the fuel pump relay will click on and off rapidly, cutting fuel making it near impossible to accelerate.

Unplugged, the car accelerates fine, appart from the odd single click of the fuel pump relay (and the idle jumping from 1200 to 1500.. up and down, up and down). Revs out nicely, and boosts hard and fast.... until it gets to the next problem.

My boost is somehow limited to 9-10 psi. The more i drive and boost, the lower that gets until its about 5psi. The cut isnt a single, brutal one like a fuel cut, its more like a 'soft' cut. a relay clicks REALLY rapidly and it wont boost higher.

One thing i did think, was because my IC pump is dead, could the intercooler be getting too hot, and causing something to go 'OH NO!'? detonation and knock sensor? I get the CEL 24, but i think thats from the IAC being unplugged (24 Air control valve Air control valve inoperative (Abnormal signal produced in monitor circuit) Prevents abnormal engine speed using "fuel cut" in relation to engine speed, vehicle speed, and throttle sensor position X X).

I have the one way valve in so the MAP sensor will only see vacuum. didnt change anything.

This happens with both the STI and the WRX ecu.

[beatersubi]

Check your grounds. I had a loose ground on the intake mani(main engine ground) and my ignition relay was clicking very rapidly(buzzing). It also gave me some weird codes.

I think people underestimate the importace of having solid grounds.

[KwS]

i added more grounds to the block and manifold, going back to the battery and to the strut tower, that didnt change anything.