Maf

[stanzz]

I need to know some information on the MAF sensor in my 93 Altima.

Could you tell me what the signal voltage from the MAF should approx. be when the car is running and the engine is revving ( between 3000-4000 rpm)? The haynes manual says it should slightly increase from 1.7 volts but should not reach 4.0 volts.

When I tested mine, the signal voltage did not pass 2.0 volts ( with the engine revving to 4000 rpm) , and I was wondering if this was possibly a faulty MAF sensor.

Thank you.

[Q45tech]

The graph of the voltage vs air flow is exponential [to the 3.5 power].

The only way to know for sure is to compare units. EXACT equal conditions of RPM and TPS voltage [engine load].

X voltage of MAF will create Y millisecs of injector opening time at Z rpm with Q units of TPS voltage.

Easier to test HP peak rpm at WOT load ~~ 4.0 volts.

They don't give exact voltages because the MAF voltage will change with temperature, altitude [barometric pressure], and humidity.

The ecu won't throw a code if the MAF seems [+-30%] close but not very accurate.

[stanzz]

Can anyone test their MAF signal voltage and post the results in this thread so I have an idea if mine are in spec?

(I'm really more concerned with the signal voltage results you get when you rev the engine.)

Please and Thanks.

[s13sr20chris]

freereving will not give a really high maf voltage. you would have to rev under load to get up there.

[Q45tech]

AGAIN the voltage will vary with air temperature and barometer [altitude and pressure] and humidity...........plus there is a +- 3% calibration accuracy at low flows.