Idle drops when gas pedal released
 

Hmm, I did search this but I didn't have any luck...(my ignorance I'm sure).

My '87 924s starts fine and has no trouble maintaining a steady idle of about 950 rpm; however, after revving the engine and releasing the gas pedal the tach falls to about 900 and then goes back to 950.

Is this symptomatic of a vacuum leak or is it something else? All suggestions greatly appreciated.

Sounds normal to me.

Clifton

Perfectly normal for Bosch injected cars with the "barn door" airflow meter. You let your foot off the gas, the flap in the airflow meter snaps shut, and it takes a second for the idle air bypass to take over.

Whew! Thanks everyone!!!

Ill take "What is, slow to respond engine control systems from the 80's" for $500


Regards
Dave