MAF elctric connections diagram

[THE NEW GUY]

Does anybody have the diagram to know what exactly does all the connectin pins in the MAF connector? Where to meassure voltage signal to the ECU and what voltages to expect?
thanks

[Tapani]

Pins are numbered 1 to 5 starting from the right, looking at the connector from the harness side.

+12V supply, red wire, pin 1
ground (shield), black wire, pin 2
ground, black/red wire, pin 3
MAF signal 0-5V, white wire, pin 4
not used, pin 5

Tapani

PS If you get the ECUtuner or something similar you can look at a lot of stuff with your laptop, including the MAF voltage.

[THE NEW GUY]

Originally Posted by Tapani

Pins are numbered 1 to 5 starting from the right, looking at the connector from the harness side.

+12V supply, red wire, pin 1
ground (shield), black wire, pin 2
ground, black/red wire, pin 3
MAF signal 0-5V, white wire, pin 4
not used, pin 5

Tapani

PS If you get the ECUtuner or something similar you can look at a lot of stuff with your laptop, including the MAF voltage.

Man, that is exactly what I need: what is Ecotuner? is it a software? will I need a connector? Where to get it? thanks for your help man. Tell me one thing: The ECU varies the injection duty cycle accordingly with the MAF output voltage or mainly acoording to the throtle position or vacuum? I know all of them applies, but there's a prioryti...

[Tapani]

Oh,

Start by browsing all threads in the mod area, ecutune projects - lots of other info available too - do a search.

Lot's of more stuff:

www.ecutune.com (also the ECUtuner is available from Micheal)

and

http://www.alcyone.org.uk/ssm/index.html

to begin with :-).

There are plenty of more educated people on this forum than me, but the fuelling maps are three dimensional - rpm, load, AFR, and load is a function of MAF voltage. Most everyday driving is done in closed loop mode though, and thus AFR is controlled according to the O2 sensors.

Fuelling wise engine vacuum is only used to adjust the fuel pressure - and that is a simple mechanical FPR at the rear end of the RH side fuel rail. TPS signal is used for a number of corrections, but it is not the main parameter.

For a set of factory manuals pls refer to:

http://phantomotaku.com/SVX/

and chapter 11 fuel injection for a system description.

With the ECUtuner you are also able to monitor the ignition advance in real time - but take friend with you to play with the lap top or let her drive..... :-)

Enjoy,

Tapani

[THE NEW GUY]

My friend: please let me know if our MAF have a temperature sensor to inform the ecu about the air temp that is comming into combustion chamber.

[Tapani]

No, there's no air temperature sensor as such. Only speed - density systems need one to figure out the mass flow: Atmospheric pressure, manifold pressure and intake air temperature data are used to "look up" the air mass value from programmed engine volumetric efficiency tables. Both systems have their pros and cons - a Saab Trionic 7 has both (and lots of other interesting features)... :-)

Tapani