From: Wally Plumley [wplumley@bellsouth.net]
Sent: Wednesday, October 04, 2000 9:43 AM
To: 928
Subject: [928] Re: Need help with low cold start idle RPM

At 10:59 PM 10/3/00 -0400, Phil Desmarais wrote:
>
>      I am trying to determine the cause of low RPM idle at cold start.
>      My 86' 928S automatic starts fine, but the idle is only running
>      between 600 and 700 RPMs when cold. When the engine reached normal
>      temperature, the idle increases to between 1100 and 1200 RPMs.
>
>      Is there an idle control component controlling this or is this a
>      function of the computer? Can this cold idle RPM be increased without
>      effecting the normal temp idle speed?  Can some one walk me through
>      some diagnostic steps to determine what is causing this?
>
>      Thanks in advance, Phil, PCA member 1998126538

Your car has an idle control system that should control the idle speed hot 
or cold.

In your case, the cold idle speed is correct (spec is 660 - 700) and the 
hot idle speed is too high. It is possible that the idle speed has been set 
improperly.

To adjust the idle speed:

Warm the engine.

Look on the top front of your engine, just under the cross-bar and just 
behind the oil filler cap, and located a round black plastic cap. Carefully 
remove this cap (which may be brittle) to uncover three wire connectors. 
They are usually arranged with one on the right and two on the left (as you 
face the plug).

Connect the single connector on the right to the top connector on the left. 
This temporarily kills the idle speed controller.

The idle speed control screw is located on the throttle housing (not the 
mass air sensor!) down under the intake pipes. Adjust idle speed to 660 - 
700 RPM.

Remove jumpers, close cap.


Wally Plumley
928 Specialists