HELP: Delayed throttle input

[r32_gtr]

I have a 96 black top SR20DET. For some reasons, the engine responses slow to the throttle at idle. Like if I try to rev it up with a sudden wide open throttle input, it has a second delay before the engine actually revs. It's worse when the engine is cold. I have driven other SR and it's much quicker in that response.

I have swapped MAFs, ECUs, changed spark plugs, checked timing... the problem is still there. I suspect it's the MAF wiring but just want to ask if anyone of you has experienced this before I rewire the MAF.

Thanks in advance for any inputs...

[mrmephistopheles]

Hubert: you might want to check your TPS to make sure it's functioning properly. Sounds like you're experiencing alot of tip-in retard.