M30 air flow meter test?

[evodan]

Does any one know how to test one of these bhoys and what values I should get, just trying to optimise the 335 running.
Cheers

[BMW_YARD]

Best visual way of doing it is with a 'scope, you could do basic test with a multimeter but never as reliable as a 'scope.

[evodan]

Still have no idea how or what values to look for, anyone?

[Brianmoooore]

Still have no idea how or what values to look for, anyone?

What do you mean by values? As BMW Yard says, you test an AFM by putting a small voltage across it and monitoring the voltage at the wiper as you slowly open the flap by hand. Should be a smooth transition with no glitches or spikes.
If you mean how do you set it up, then that's a job for an exhaust gas analyser, preferably on a rolling road.

[evodan]

Ah… thought that it would be a simple check for resistance with a meter but seems not.
There is a 4 pin multi plug on the AFM, at what pins is this voltage applied and how much and at what pins should the change in voltage be observed.
Or can a battery be used with an inline meter, again what voltage.
This kind of stuff is not ma strong point as you may have realised so please keep it simple for the dumb asses like me.

As for setting it up was not aware of any adjustment on the M30 thought it was all ECU controlled?

[evodan]

Still don't have the answers I need, nobody got anything to add to this?

[Brianmoooore]

Assuming the M30 AFM is similar to the M20 one, then the adjustment is the tension on the coil spring. Apply 5 or 6 volts across pins 4 and 3, and monitor the signal across 4 and 2.

[evodan]

Thank's mate will give it a go.

[Brianmoooore]

Better state here that my main computer knackered itself last night, and i'm writing this on a steam driven laptop.
There's an awlfull lot on info on the hard drive of that computer that I can't access. One of these is checking if a M30 AFM has the same connections as a M20.