Are they the same? I have a feeling that the VR4 has a different FIAV or something because I am on my second TB and neither one held an idle at 750-800 both were 1K plus...But when I swapped my original on, it worked just fine...Had leaks but it idled properly. I have tried adjusting the BISS screw as well as grounding the timing and diagnostic pins to no avail. I also tried taking off the ISC connector still no change.

Thanks in advance,
-Manik

As far as I know, the only difference is 90 style, vs 91-94. Turbo is obviously different than N/T from factory, but are interchangeable. Have you tried adjusting the TPS sensor? The ECU needs to know the engine is at idle, with the correct TPS voltage, and the closed throttle plate switch. The BISS is just to fine tune, but if the others are out of whack, it will never work.

I have used link to adjust the voltage to the correct range, and it still hasn't fixed it...Maybe I will try zeroing out link and adjusting it that way /ubbthreads/images/graemlins/idea.gif

I try to not adjust TPS offset in Link. Make sure you're idle switch changes when you are on/off the throttle. If not, you can simulate the idle switch of TPS readings. That helps a lot of cars. Also, make sure your throttle plate closes enough, by adjusting the idle stop switch.

Not really relevant to your problem but the idle speeds for 1g and GVR4 are slightly different.

Correct, but I think it's only 50rpm, and that's target based by the ECU anyway. But good info.