If IAC cleaning and or replacement didn't help check this TSB published by ford
99-7-1 HIGH IDLE - HARSH TRANSAXLE GEAR ENGAGEMENT - SABLE BUILT THROUGH 9/16/1996 AND TAURUS BUILT THROUGH 8/16/1996 - ALL 3.0L VEHICLES
STALL - STALLING ON TRANSAXLE ENGAGEMENT - COLD ENGINE - 3.0L 2-VALVE VEHICLES ONLY
SURGE - SURGE AND/OR POWER SHUFFLE BETWEEN 56 AND 72 KM/H (35 AND 45 MPH) - 3.0L 2-VALVE VEHICLES ONLY
TRANSAXLE - AX4S AND AX4N - HARSH ENGAGEMENT - SABLE BUILT THROUGH 9/16/1996 AND TAURUS BUILT THROUGH 8/16/1996 - ALL 3.0L VEHICLES
Publication Date: APRIL 6, 1999
FORD: 1996 TAURUS
LINCOLN-MERCURY: 1996 SABLE
This TSB article is being republished in its entirety to delete the statement in the Action about PCM replacement for certain date range vehicle builds.
6-10A, 6-10B, 6-10S, 6-10T, 6-14A, 6-14S
WARNING: THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.
A high engine idle can occur causing a harsh transmission gear engagement when moving the gear selector for all 3.0L engines. The 3.0L 2-valve engine may also stall when the transaxle is moved into the "Reverse" and/or "Drive" position with a cold engine and/or the vehicle may experience a surge or powertrain shuffle between the speeds of 56-72 km/h (35-45 mph). These concerns may be caused by the Powertrain Control Module (PCM) calibration.
Reprogram the PCM. Refer to the following Service Procedure for details.
Confirm the symptoms of high idle with harsh transmission engagement. Check emissions decal to verify vehicle does not have the latest calibration. Reprogram the PCM using the Service Bay Diagnostic System (SBDS) or New Generation Star (NGS) Tester to the latest level calibration.
Road test the vehicle and perform the EEC-V Self Test. Confirm there are no Diagnostic Trouble Codes (DTCs). If any DTCs appear, refer to the 1996 Powertrain Control/Emissions Diagnosis (PC/ED) On-Board Diagnostics II (OBD II) Service Manual for detailed diagnostic and repair procedures.
Obtain an Authorized Modifications Decal (FPS 8262 - obtainable through DOES II, 25/pkg) and list the date, dealer number, and summary of modifications performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.
THE FOLLOWING MODIFICATIONS HAVE BEEN MADE:
Reprogrammed Powertrain Control Module (PCM) per TSB 99-7-1
THESE MODIFICATIONS HAVE BEEN APPROVED, AS APPROPRIATE, BY EPA AND CARB.
Thursday, October 28th, 2010 AT 7:58 PM