sr maf key on engine off reading, is it important?

[justinbyrant]

so I have been looking and I see that the maf should read around .2v with the key on and the engine off, mine reads .8, I cant get it to idle or run well enough to test the maf with the engine running so I cant get a idle reading and a 4k reading, is the engine off reading an indication of the maf being bad or can they read .2v to 1v or does it really need to read down to .2v?

[justinbyrant]

update, got a *new maf, used, guy said it was good, I trust him well enough and he just gave it to me so no real reason to lie, however this maf reads .9v engine off key on, I cant get either maf to read over 3v when running however that's with zero load, is the maf supposed to read 4v at 4k with load or without or should it matter?

also when I unplug the maf the idle smooths out but it blows smoke like a diesel, this thing is just baffling to me

[Kingtal0n]

the maf outputs a 0 to 5v parabolic voltage curve. the computer converts the signal into a mass/time. Since the curve is parabolic you need basic algebra skills to understand what the voltage output should be at various mass flow rates. You should look up a parabolic curve for whatever sensor you are using and delineate the output voltage based on engine flow at whatever rpm/load the engine is at.