Intermittent dropping throttle on 3.2
 

Hi all,

Another tech question for everyone.

Occasionally in second gear on my 87 911 when I'm very lightly on the gas I will notice maybe 1-2 seconds of dropping of rpms/gas, followed by the engine resuming to normal operation. If I push the pedal harder during this dropdown period the throttle resumes immediately as normal. I don't notice it when I'm giving it a a good amount of gas, just when I'm very slightly on the throttle. Based on the sound of the engine it sounds like I've taken my foot further off the gas even though it is in fact in the same position. This may be somewhat normal, just curious and trying to learn more about the car :)

Thanks!

Eliminate mechanical suspects: here is my thread: http://forums.pelicanparts.com/porsche-911-technical-forum/609976-fix-binding-accelerator-not-pedal-bell-housing-bushings-not-even-tunnel.html

Throttle contact out of adjustment? Old ignition cables?

Does the car sit a lot? Old gas? Are the ignition components old? Vacuum leak could be possible, or clogged injectors.

Car is a daily driver so it doesn't sit and the gas is fresh. Will investigate the other mentioned issues and report back.

I had something similar (slight power loss at 3200 rpm no matter the throttle angle) so I suspected a vacuum leak. I tightened and reseated induction hoses and places where un-metered air could leak in and the problem went away. In the end though, I do not know exactly where the leak was.

Spraying starter fluid near the hose ends can pinpoint vacuum leaks but that just makes me nervous. I just worked and tightened everything I could.

Good luck.