2.9l Mpfi Ford Bronco II I

1. Turn off all lights and accessories. Place transmission in Neutral. Ensure A/C and heater selector is turned off. Bring engine to normal operating temperature and shut off. Disconnect the idle speed control air by-pass power lead.
2. Start engine and operate at 2000 RPM for 2 minutes. Allow engine speed to drop to idle and ensure base idle is within specification. If base idle speed is not to specification, adjust speed at throttle plate stop screw. (Scheme 2)
3. Turn engine off. Restart and ensure base idle speed is correct. Readjust if necessary. Turn engine off and reconnect power lead to ISC air by-pass valve. Ensure throttle plate is not sticking in throttle bore.

Scheme 2

HOT (SLOW) IDLE RPM SPECIFICATIONS

Scheme 3

1. Turn off all lights and accessories. Place transmission in Neutral or Park. Ensure A/C-Heat selector is off. Apply parking brake and block wheels.
2. Bring engine to normal operating temperature and check for vacuum leaks downstream of throttle plates. Disconnect spout line (single line connector), or remove shorting bar (double line connector), and ensure ignition timing is correct. Readjust if necessary.
3. Shut off engine and disconnect air by-pass valve assembly connector. (Scheme 3) Remove PCV entry line at PCV valve. Install Orifice Tool (T86P-9600-A) in PCV entry line. Orifice diameter is.2" (5 mm). NOTE: If electric cooling fan comes on during idle set, unplug fan motor or wait until fan shuts off before starting procedure.
4. Start engine and let idle in Drive or Neutral. If idle speed is not within specification, adjust throttle plate screw. After idle has been set, shut off engine.
5. Restart engine and check idle speed after 3 to 5 minutes. If not within specification, repeat step 4). After idle speed is within specification, shut off engine, remove orifice tool and reconnect PCV entry line. Reconnect spout line (single line connector), or replace shorting bar (double line connector).
6. Reconnect ISC motor and cooling fan. Verify throttle plate is not stuck in bore and that throttle plate stop screw is setting on rest pad with throttle closed. Restart engine. After 3 to 5 minutes verify that engine RPM is within specification.

HOT (SLOW) IDLE RPM SPECIFICATIONS