Originally Posted by
Arne
So after slowing down at a high vacuum (using engine brake with throttle closed), the idle speed is lower than normal. A blip of the throttle brings it back to normal. I wonder about worn throttle shaft bushings. High vacuum while slowing down is perhaps sucking the throttle plates tighter in the throttle bodies? A blip frees them?
Because of my poor English, I may have you misunderstood the condition. The idle speed comes lower than normal, and it recovers gradually after about 20 to 30 seconds or more which depend on how long I use engine brake. So I think the throttle plates do not stick in the throttle body.
Edit - Just to clarify - My experience with MFI and prior owners' attempts to "fix" things reaffirms that adjustments to the MFI mixture should be the VERY LAST thing to try. All other things should be checked, adjusted and corrected first.