alfa 33 1.7 16v uses a VolumeAF sensor,
alfa 145 1.7 16V uses a MassAF sensor.
alfa 145 1.3 I.E. uses a simple air pressure sensor (same as alfa 33 1.3 I.E)
Theorically MAF or the simple air pressure sensor
are better than VAF, because of a bit less air resistance,
but for elaborations also a bigger VAF
could be a possibility (from alfa 155/164 bigger engines as v6).
If you are planning to use MAF from 145 1.7 16v
I think that to get advantage over the original VAF of alfa 33 16V
you have to use it with aftermarket ECU / or 145 remapped ECU.
Because if you use the complete electronic system from 145 it was
a bit low performance/low emissions respect the ML4.1 of alfa 33 16v ??
(and you should also swap the flywheel as it have a different
tag sensor angular position).
May be if you can use an aftermarket ECU,
a good way could be use a simple air pressure sensor?
There are also some types of these sensors with both negative
and positive pressure reading for use on over-charged engines;
I read maybe on this forum that using air pressure sensor on
boxer 16v you have the problem of stabilize the pressure fluctuations
at the sensor at low revs but it can be done with some tricks.
I had founded this:
- 145 1.3 I.E. boxer : IAW-Marelli system with a simply air pressure sensor
- 145 1.6 I.E. boxer : Motronic MP3.1 system with air pressure sensor
- 145 1.6 I.E. boxer : GM system (don't know if MAF or air pressure sensor?)
- 145 1.7 16v I.E boxer: Motronic M2.10.3 system with MAF sensor
see image at page 18 of this: