I was checking the throttle body today. My Haynes manual says to disconnect the vacuum line that goes to the MAP sensor and hook up a vacuum gauge in it's place. Then let the engine warm up to normal operating temp. The manual then says that after engine has come up to temp confirm that there is NO vacuum. Is that correct? I have 18-20 inches vacuum all the time from there. If there is'nt suppossed to be vacuum does that mean the throttle body is worn out? Could somebody please set me straight on this.
Thanks,
Tim


93 Accord LX
Manual tranny

 

no you have vaccum as soon as your throttle plate is closed.

what are you trying to first? with boost?