Instead of vacuum gauge: multimeter on MAP sensor

[Clev]

Originally Posted by wikityler

I did this with my acclaim. I found that the dmm I was using, having 1/2 second measurement, wasn't responsive enough. Something a bit faster, and it would work great.

What about an analog multimeter?

[NiHaoMike]

Originally Posted by Daox

Most MAPs have voltage outputs. I'm sure some maker somewhere thought they'd be smart and put in a frequency output on something though.

And many modern multimeters also measure frequency. But if it outputs a frequency in the audible range, there's an even better way. Tap into the signal with a series resistor and capacitor and connect it to a very cheap audio amplifier. Then just listen to the tone while driving.

[modmonster]

is a MAP sensor the same as a MAF sensor? Mass Air Flow sensor? if not what would measuring a MAF tell you?

[wikityler]

Originally Posted by modmonster

is a MAP sensor the same as a MAF sensor? Mass Air Flow sensor? if not what would measuring a MAF tell you?

Map is Manifold Air Pressure. It's like an electronic vacuum gauge. MAF is Mass Air Flow, it measures the quantity of air entering the intake.

[Nevyn]

I thought it was Manifold Absolute Pressure?

[Ford Man]

Originally Posted by Nevyn

I thought it was Manifold Absolute Pressure?

Correct

[modmonster]

does voltage of MAF sensor indicate the engine load?

[jazzie604]

Originally Posted by modmonster

does voltage of MAF sensor indicate the engine load?

not really, it measures the volume of air entering the engine. this can be used as well, since the less air the engine is sucking in the less fuel it is adding to the engine. Problem is MAFs use a hertz reading which is more difficult to monitor.

[modmonster]

my BOSCH MAF gives a voltage signal 0-5v. this is calibrated to air flow rate which is directly proportional to fuel flow rate. boscheSensors (page 57)

all we need do is data log voltage and speed and we have a method of calculating MPG. or alternatively you could just display the voltage on a meter and do the mpg calculations in your head! at constant speed you know what voltage to expect, if mods reduce the voltage then you know they save fuel.

[modmonster]

can a sat nav be set up to display trip average speed?