Trying to nail down the problem before dropping the money on a new MAF sensor, any ideas or help are appreciated:

Started with the MAF sensor code. Searched forum and checked for other symptoms of MAF issue: low rough idle, can't accelerate over 4500 RPMs. Feels like there is no power, can hear a ton of air getting pulled in but very little acceleration. Half the time these symptoms are present at start up, half the time car runs a little better (can accelerate past 4500, have more power, idle is less rough).

Cleaned the MAF sensor, great results, car ran best it has in years, CEL went away. Only lasted about two days then everything came back. Cleaned sensor again but no success this time.

I have also noticed that even when the car is running "better", voltage is all over the place while driving. It will drop to as low as 12.6 then kick back to 13.9 while driving, not only at idle.

Could this all be a bad MAF sensor? Could something be wrong in my power system as well? Bad wire? what wires should I be checking?

Thanks.

 

Bump... Put in a MAF sensor from another VIII (have no reason to believe this sensor was bad), but it didn't help. Problem seems to be happening more consistently, especially bad start up: Turns over fine and then drops to 400-500RPM and then gets real rough.

Any help or thoughts would be appreciated.

 

just delete the MAF sensor and go speed density

 

Youre probably having un-metered air check all clamps and hoses

 

X2

 

My thoughts on this issue would be alternator or battery related. If you're not getting enough juice to the plugs it would and could have all these symptoms. Voltage drops at cruising speeds is a dead give away imho. Good luck op.

 

I had the same issues with my evo8. My evo sat for about 6 months so i was assuming it was a fuel issue. I was having cams, evo 9 turbo, valve springs and retainers, and an e85 tune done to my car so I had my tuner check that issue out while he had the car. What he found was one of the pins in the maf sensor connector was pushed out and was not making contact. Hope this helps.

 

Update: hadn't gotten the car fixed because I was waiting on an insurance claim after a major hail storm ($5000+). Took the car to a shop to see if they could diagnose anything. Shop said they checked all the wiring and the correct voltage is passing through, but there is only power going to the MAF sensor and no signal coming out to go to the ECU.

Ordered a remanufactured MAF (changed battery in the mean time, old one was completely drained), no change, shop still says signal going to MAF but nothing coming out. The shop says I have been unlucky and have had 3 bad MAFs.

Is it likely they have all been bad? Could it be tune/ECU related? Would a boost leak cause the lack of signal? Could something else wrong with the car be ruining each of the sensors as soon as I install it? Any suggestions appreciated.

 

did you find the issue?

 

In my experience that remanufactured maf is only going to cause you to chase your tail because they need to be tuned for. The scaling is off, I don’t know why that is but the mafs that I logged; remans by standard motor products and blue streak read way different than stock. It would help if you had some sort of wideband on the car to see if it was running lean/rich.

 

I just got my remanufactured MAF sensor and I still have the CEL on. My evo 8 turned on smooth finally idk if it might be cus the engines warm idk. I get my tunes a English Racing so that's the move I guess.