Fixing all your keys
AO Silver Member
Join Date: Mar 2001
Location: United Kingdom
County: Tyne and Wear
Re: Disappearing Revs - Please Help
Have you looked at the resistance that holds the butterfly closed? It may be that hitting the accelerator hard is causing the butterfly to open and its momentum, coupled with the sudden airflow changes is causing it to overshoot and then occilate breifly in the airflow until it settles to its proper position. This occilation would be compounded greatily by the airflow moving over the butterlfly as it woudl exagerrate the movements.
Admittedly its a long shot but it does sound possible that the butterfly is moving a bit too freely. Is the stepper motor fitted properly? Any chance you could slap another throttle body on briefly as a test?
Sorry, best I can come up with.