the_buch

Drove away from the audio shop today after install of new sound system, and the car stalled at the first stop light. I thought maybe I was preoccupied and just blew it, but this happened at every full stop. It runs absolutely normally in every other way except for at idle when the revs just drop off to nothing.

Eventually I had to pull up to every light or stop sign and just before it died work the gas and use the parking brake to hold position. If I take my foot off the gas it just drops off to nothing and stalls. It then starts right away and is ready to go again as long as I keep some gas application.

I can't think of anything that could go wrong with the hookup to cause this, but wonder if there is something about the system having to relearn idle after the battery has been disconnected for several hours, or possible jostling of a critical relay or something during the wiring process. If anyone has an idea for me to try, I would greatly appreciate it.

Thank you,

Monique

If the shop disconnected your battery, this could be the cause. The ECU loses its memory and resets to a baseline code. It must "relearn" how to manage the engine. Steve Weiner detailed a reset procedure some time back. It is in the archives.

Apparently, this is more so with OBDII cars ie, '96 and after w/Varioram.

texas911

Was your radio on? They might have connected the new audio stuff directly to your battery and is draining it, might be time for an Optima battery.

JasonAndreas

If the stereo shop reconnected the battery and then even just touched the gas pedal the first time they started the car afterwards then that will cause all sorts of idle problems. You could try disconnecting the negative lead on the battery for a few seconds and then reattach and start the car. Just remember not to use the gas pedal on the first restart. If that doesn't work you could always inform the stereo shop that they F'ed up your car and they will now have to foot the bill for your $100/hr mechanic to troubleshoot.

Steve Weiner-Rennsport Systems

Doug:

No worries, Sir.

Call me and I'll tell you how to do the MAFS & throttle body adaptation and that will take care of it.

the_buch

This was a very interesting experience ... I struggled all the way home on my long commute and had to restart and then feather the throttle at every traffic light.

Ultimately, as indicated above, about 20 stops, 60 minutes of driving and 50 miles later the performance of the car at idle has resorted itself and it is behaving normally again. This has been a very informative lesson

Steve ... I will definitely call you as soon as I can get to it, since you may be suggesting that I should be doing another adaptation from scratch??

Without this list I would have been having a c*%p about this so early in my 993 experience!

gjtrek

I've heard about this phenom before. The subwoofers are draining horsepower off the electronic grid which in turn is responsible for the increase in decibels and decrease proportionally in rpm to the point where the negative downpressure of the biorythms of the cam chain drag exceeds the optimum pressure of the varioram output and...yep..you have the dreaded stalling.

Steve Weiner or ViperBob have the cure. The secret is to turn down the volume!!

Regards, Gary