Re: RE: JET opinion * Your opinion wanted???

From: Bob Tom (tigers@bserv.com)
Date: Fri Oct 30 1998 - 15:23:28 EST


Some info. about PCM under WOT.

This applies to the 97 PCM ... can't speak for other years.

The PCM operates in 2 different modes: Open Loop and Closed Loop.

During Open Loop modes, the PCM receives inputs and responds according
to "preset PCM programming". Input for O2S is not monitored during
Loop Modes.

During Closed Loop modes, PCM monitors O2S input. This input indicates
to the PCM whether or not the calculated injector pulse width results
in the ideal air-fuel ratio (14.7 to 1). By monitoring the exhaust oxygen
content via the O2S, the PCM fine tunes the injector pulse width.

The fuel injection system has the following modes of operation:

Open Modes: Ignition switch ON
             Engine start-up (crank)
             Engine warm-up
             Acceleration
             Deceleration
             WOT <==================ignores O2S and provides a
                                     predetermined amt of extra fuel
             Ignition switch OFF

Closed Modes: Idle
               Cruise

PCM inputs under WOT:
  Battery voltage
  Crankshaft position sensor
  Engine coolant temperature sensor
  Intake manifold air temperature sensor
  MAP sensor
  TPS
  Camshaft position sensor signal

Bob
Burlington, Ontario, Canada
tigers@bserv.com

Current: '97 CC Sport, 5.2L, 3,55 auto., Gibson dual, K&N filter element.
          '85 Shelby Turbo Charger, 2.2L, manual.
          '70 Challenger, 383-4bbl, auto.
Past: '71 Road Runner, 340-4bbl, auto.
          '70 Duster 340, auto.



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