MAP map or MAF map

[robert dingli]

Hi everyone, 

my own misunderstanding seems to have caused a bit of confusion
regarding MAF sensors.  As Rod and Bryan have pointed out, the hot wire
sensors operate on a different principle to the moving vane type. 

The types which I have been in contact with (Bosch Motronic and Ford EEC)
both utilize air temp sensors and the Ford system uses a pressure sensor
for barometric compensation.  The Bosch is a moving vane type and the
Ford (8 cyl SEFI) is a Hitachi hot wire unit which has its own air temp
probe in addition to a plenum mounted sensor.  The six cylinder has exactly
the same sensors minus the MAF sensor and uses a speed density algorithm.

In future, I'll qualify my comments by detailing the system that I've
encountered first hand.  As a suggestion, perhaps we could collate our
collective OEM knowledge in some sort of list.  For example,

Make:  Ford Falcon (Australian build)  EA77 4.0 litre six cyl
ECU: Ford EECV  MPI speed density system, multi coil crank trig ignition
etc.

Robert

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             Robert Dingli           r.dingli at ee.mu.oz.au

Power and Control Systems                 Thermodynamics Research Lab
Electrical Engineering                    Mechanical Engineering
   (+613) 344 7966                           (+613) 344 6728
  University of Melbourne, Parkville, 3052, Victoria, AUSTRALIA
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