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MAF Sensor Voltage.. What values do people have ?

Discussion in 'VY Holden Commodore (2002 - 2004)' started by Sdel179, Oct 29, 2015.

  1. Sdel179

    Sdel179 Member

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    I have been trying to find out what are the voltages of the MAF sensor in the Ecotec motor..the check engine is not chucking any codes.. Before I start replacing the MAF and Oxygen sensors I'm just wanting to know if anyone knows the stock values when the motor is hot.. At idle mines 4.32 volts and as I increase the throttle it drops to mid to low 3 volts.. If anyone is bored has the multimeter around I'd really appreciate it if they can reply with there values from the Ecotec MAF.. I inserted a paper clip into the back of the plug so I didn't need to cut wires.. Cheers guys.. The story so far.. The car has a bad thudding under load only once it's starts to warm up.. It's fine for the first few ks..then once it warms up its thumping away and lacks power.. It's shown to retard timing and run rich when this happens.. I have been advised replace the MAF oxygen sensors maybe also the knock sensors as well.. I have just had the inlet manifold gaskets done, new plugs and leads and tried another set of known working coil packs all 3 and another DFI module and that's made no difference.. So it would seem if it's a sensor it would be one that shows a open loop cold the once warms it creates the thudding.. I know I have just posted but I have now spent over $700 and no improvement bar the fact I have no oil in the coolant now..
     
  2. Jxfwsf

    Jxfwsf Well-Known Member

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    No point measuring the voltage, the output is a frequency.
    All you're getting with any cheap multimeter is a random voltage. The frequency output isn't DC (and technically not AC either), all you're seeing is it's doing something.
    The meter will not be quick enough to show any accurate values, as you have seen, it'll be the same voltage but as the frequency changes the meter can't keep up and shows nothing of use.
    You need an expensive dmm, scope or scantool to log and view the output correctly.
     
    Last edited: Oct 29, 2015
  3. Sdel179

    Sdel179 Member

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    Sounds like it would be cheaper to get a 2nd hand MAF and try it :) thanks for your advice
     

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