I keep changing MAF sensor eveyr other 4 or so days???
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This is a discussion on I keep changing MAF sensor eveyr other 4 or so days??? within the Tuning: Electronic Engine Management forums, part of the Tech & Modifying & General Repairs category; Hi, My MAF went bad, then started hessitations, timings pulled etc. Then I got a brand new Denso one, as ...

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    Red face I keep changing MAF sensor eveyr other 4 or so days???

    Hi,

    My MAF went bad, then started hessitations, timings pulled etc. Then I got a brand new Denso one, as can be seen here: Denso 197-6040 Mass Air Flow Sensor
    Worked for about4 days, then gone. Bought a CRC MAF cleaner, get the MAF out, cleaned as per instructed, which was already shining in both temp bulb and wires hidden inside.
    No change, MAF gone. Then bought another one and BAM, gone! Again as in my luck, no one can make sense of this including my mechanic. Air ways are shining clean, from CAI to whatever I can see.
    I'm using this CAI btw: APS High Flow Cold Air Intake System.

    Help, anyone?
    Any though will be greatly appreciated, even unbelievably silly ones 'cause from my point of view, this is the silliest thing ever happened to me in my 16 years of scooby owning.

    I'm considering the thought of removing MAF altogether and putting an external control unit and working by MAF, but I'm a VERY daily driver, meaning I'm spending at least ~2 hours a day, half of that time being in a traffic that comes to a halt after every inch of moving forward.

    *SIGH*

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    Village Idiot McBill's Avatar
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    have you considered some sort of electrical short or bad ground? I'm not particularly knowledgeable in terms of MAFS's but I have had some pretty weird issues with shorts or bad grounds before. One time, in my 84 z28, I kept roasting Ignition modules and could not figure out why the life of me. Come to find out, my uncle had the same problem once in the past, and it was all caused by a bad voltage regulator in my alternator. It was cranking around 15volts when it was only supposed to do 12-13. That was just enough to toast the module.

    I don't know if this will help or not, Most likely not but that's just my two cents.
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    How do you know the MAF is toasted? Are you getting a DTC? You have what car? Which intake? The 65mm or the 70mm?
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    I have a 07 STI with a forged engine using CP internals, 65mm APS CAI, 750cc injectors, one step colder sparks, walbro 255l pump, varex muffler, with a high flow catted dp and a custom tune. Other than those, everything is pretty stock. Car is at a 80k kms.

    I know the MAF is toasted, as; when I put a new one the difference is as night and day. Response at light speed, no meaty gas pedal, engine is running almost w/o a hint of vibration, AFR is perfectly fixed at 14.7 at idle, and 11.1 at load, and it feels like the car is all stock and just bought. Then slight hessitation starts building around rpms of leaving closed loop, ~2500. Then it gets worse with every other km. After a while, which differs from three to five days, AFR is no longer sane, its dancing around rich to lean, 12-17 at idle, and 10-12 at load. I reset ECU or I reflash but it does not feel like the day I put the new MAF in. AFR never fixes at needed values even after a reset, and the car does feel sluggish, no hessitation for a Little while but it gets bad real quick. Then I replace MAF and its like brand new again. No cleaning solved the problem.

    But the real annoying thing is no light on dashboard, everything looks perfect except me banging back and front while car cuts the fuel as ı,n very slowly accelerating from low rpms at traffic or trying to launch the car slowly. It even stalls from time to time but not frequently. Until I reset ECU or replace MAF.

    I am, too, thinking of shorts as my alternator was toast a while back but was repaired, not replaced, but wouldn't a toast MAF give check engine light? Is there a possibility that shorts might be cooking the MAF and its cannot be detected?


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    He simply abides. SD_GR's Avatar
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    Do an old and new MAF differ electrically when tested with a multimeter?
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    Registered User maus's Avatar
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    Are you disconnecting the battery or reflashing your ecu when you hook up the new MAF?
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    Now that is something I never thought..! I'll do that ASAP, that is when I get a hold of a another new MAF. *SIGH* Thank you SD_GR!


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    I am disconnecting the battery before replacing the MAF maus. I pump the brake a couple of times too before connecting the battery to reset ECU.


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    Registered User maus's Avatar
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    You're resetting all the fuel trims when you do that. Might have some sort of a leak somewhere along the line, which is causing your fuel trims to be all out of wack.
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    McBill, SD_GR, how can a cars electrical system be tested for a electrical short or bad ground? If there is a problem, does it mean its always there or can it happen at some time like under load or I dont know, when ignited. I am asking this because I am having a very, very strange thing from time to time, like my stereo loses its output like %80-90 percent, but I lock or unluck the doors and it suddenly recovers. That happens during driving. It has not been doing that for a while though but there is a possibility that it has done that with my current MAF too. Strange thing is, other than stereo output every other thing is working perfectly, as all the lights, as well as the stereo itself.


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    Car has been tested for all possible mechanical problems numerous times, maus. I can say that there are no leaks anywhere. Pressure tests passed as well as fuel line and fuel pressure. We went deep into knock learning for short term, long term, dumped data logs as we drive through and what we came with was that MAF is reading false values, creating a map and overlaying that map onto static map with an effectiveness of %15-25. When we change the MAF every problem vanishes. When problems do come back, we did the same procedures again and were not able to reproduce the perfect result as a new MAF even from the get go...


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    Oh I forgot. I also have tomeika 20g turbo and HKS single plate clutch...


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    MAINEiac 11blackSTi's Avatar
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    I've never personally had this issue, but I have read many incidences that are described exactly like yours. As Donkey and McBill suggested, this sounds like the tell tale signs of a bad ground or electrical connection. Are you very experienced with electrical work? I only ask because if you aren't, it might be quicker to have the connections, wires, etc looked at by a mechanic. They would want to look for any type of corrosion or wires that have rubbed through. Seems odd that you are not getting a cell from this.

    For your stereo issues, how much work have you done to the system and how much power is going through it? You might think of doing the big three upgrade. Are your lights dimming at all during high volume?
    Upgrading a car's electrical system: do you need the big 3?

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    Unfortunately I'm not experienced at electrical work, 11blackSTi. But I'll definitely have it looked at by a mechanic this weekend. I have a hint of feeling that this really *IS* the problem. We looked into anything but this. The reason of doubt was not getting a cell, but I've put away all my assumptions and started from scratch. Because it has not been solved yet, it has to be something we did not look into and that is most probably a assumption we made earlier, that made us bypass the probability of the cause.

    I bought the car with the system on it. It has two amps and a sub size of a garderob. Jeez. I removed one amp and sub. After that, stereo started loosing power VERY less frequently. I think I'll also have it checked out, remove the other amp and go for a similar to std setup. I'm not fond of loud music, dono why I did not that before. Duh-self. Lights are not dimming at all and there is no hint of any electrical shortage anywhere else but stereo loosing sound level.

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    Update! All amps removed, cablea checked, new MAF inatalled and MAF table scaled for APS 65 CAI. All combined, its going rather well w/o any hint of power losage and hesaitation for about three days now. I hope its OK now. Thank you again ppl. I'll post another update again after couple of days. If problem persists I'll definitaly go for MAP operation way... Any ideas or suggestions about MAF vs MAP?


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