Idle speed

[Iron Bender]

I have a 94 3.2 in a frankenSHO 1934 Ford with aftermarket air. The factory idle speed is too fast so the engine is currently running on the idle ***** with IAC disconnected. It would be great to get the idle kick up when the air is on along with the cold idle. Anyone know how to change the idle speed settings in the ECM so the IAC sets at a lower base idle and air-on idle?
thanks
Jim

 

[NoSlo]

The EEC-IV already does this. Inadequate refrigerant will cause the idle to kick up too high when AC is engaged.

PCM gets signals PK/LB pin 10 (pressure switch monitor) and LG/P pin 31 (HFC out) from the CCRM. Additionally, ATX loops the overpressure cutoff ground through the PCM pin 42. Without these, it can't know if AC is running properly.

Normally the CCRM pin 21 is driven with "AC Relay control feed" from EATC. That runs the fans and AC clutch.

PCM provides output signals for low fan, hi fan, and WAC to the CCRM, based on AC operation and temperatures.

To get into the PCM, to modify for an AC compressor with higher load, you'd need a Tweecer RT or such, and modify values like "ISC A/C RPM adder in drive."