NefMoto

Hello to all I would like to ask you something about maffless setup for my car. In the last few days my MAF died and i don't have at the moment 180euros to buy a new one. So i desided to go mafless. The first think i noticed is that i was running different AFR's and that the car has better throttle response and more power. I also noticed that my ignition maps needed to be tuned because i was running at higher ignition angles from before and more cf's appeared. Can anyone tell me what will be the problem of sticking with mafless profile for ever? My car is a golf IV 1.8T AUQ engine  06A906032MJ ECU. Thank you in advance.

I understand that if the MAF if unplugged or deleted, the ECU will run from a basic MAF table; perhaps the inlet manifold model? However, the ECU will be missing its primary input for determining how much air is entering the engine and therefore will not be able to set accurate fuelling, only relying on the STFT to make adjustments. If you've got a wide-band pre-cat oxygen sensor, then I suppose this won't be too much of a problem. Overall though, I should imagine that the ECU is more likely to err on the side of enrichment rather than enleanment to protect components so you will use more fuel across the board. The only problem I can think of with across-the board enrichment is cylinder bore-wash, but I think this is only a problem at excessive enrichment.

The ECU will probably be reasonably accurate with MAF predictions during steady cruise, but dynamic conditions will be more difficult to process. Idle is difficult enough to control anyway so I guess it depends on your typical driving conditions as to how much of an issue it is for you.

You should replace the MAF sensor as soon as possible.

Doug

I'm not sure what year your 180 is, but it is possible to tune for mafless if you have a map (mass absolute pressure) sensor. The problem with this "model" of tuning is that when you add more aftermarket parts, you have to re-tune. With the maf in place, the engine is more adaptable as it can "see" the air coming in better. If you have just unplugged/ or just don't have a maf that's working properly, then TTQS is correct, you will run rich and this will damage your cat over time (assuming you have one of course!). This in turn can also wreck 02 sensors as well. I know this last part from experience!!

Thank you all for your answers i understand that without maf i have to fine tune as possible the injectors but i am lucky that i have the MAP and wideband O2 i also have the stoch cat and i pass all emission tests succesfully. As for fitting some other aftermarket parts in my car thanks to this forum i can try to recalibrate everything is needed. Besides what you were mention before are there any other possible problems that i could have in the future?The protection maps work normaly? I also noticed that with this setup i can add an open loop BOV without any problems. Thanks again.