Flusspferd
New Member
Hi everyone and Guten Abend from Germany
I’ve been reading in here since I got my 2005 td4 “Sport” about five years ago, by now I realized that the “sport” they seem to be doing in solihull must be something more like chess or replacing power window mechanisms against the clock, but I guess the car has its moments and I’d like to extend a big thank you to the fellow members sharing their knowledge and keeping these vehicles at least as roadworthy as the manufacturer intended.
I, too, have been underwhelmed by the power of the td4, especially when low in the ripp’Ems and towing my caravan during the summer, although most of the known troubles should have been shot already, including a fresh legit Bosch maf, full intake system clean, confirmed turbo operation and rigid boost hoses along with regular service. So I did what anyone on this forum would do and disconnected the maf (again) - and the car drove much better. Another duff Maf then? Checked it with another 35€ Chinese one from eBay and either that was bad out the box too, or there was more to it.
i had gotten an old code reader obd thingamajigger to clear the srs fault it liked to throw and read the data streams for rpm and air mass+temp with no maf, Bosch and Chinese maf. It turned out that the air mass increased with rpm similarly between all the setups, but without the maf, the engine assumed the highest air mass, while the two mafs returned similar (smaller) values.
Important to see is that with the maf disconnected, the ecu supposes the air entering the maf was at ~-40’celsius, when it was actually about +10’. The ecu therefore assumes the air was about 25% more dense so it oughtabeen injecting 25% extra fuel. Does that tell me if my mafs are good or bad? I say it doesn’t.
You don’t necessarily need a new maf or use a synergy if your car runs better with the maf disconnected.
The engine will always perform better if you disconnect the maf while the temperature is greater than -40,
because it injects additional fuel that would only be appropriate in -40 degree weather. Not sure why it was chosen like that, maybe being setup for -40 helps it start or idle/run if it does get that cold. So, as running something like the synergy could get you into lots of trouble in Germany, for now my way to go will be keeping a maf plugged in when my wife has it, and when i feel like it or need power to tow, unplugging the maf for xy% power increase and for whatever reason better throttle response.
Let me know what your thoughts are!
I’ve been reading in here since I got my 2005 td4 “Sport” about five years ago, by now I realized that the “sport” they seem to be doing in solihull must be something more like chess or replacing power window mechanisms against the clock, but I guess the car has its moments and I’d like to extend a big thank you to the fellow members sharing their knowledge and keeping these vehicles at least as roadworthy as the manufacturer intended.
I, too, have been underwhelmed by the power of the td4, especially when low in the ripp’Ems and towing my caravan during the summer, although most of the known troubles should have been shot already, including a fresh legit Bosch maf, full intake system clean, confirmed turbo operation and rigid boost hoses along with regular service. So I did what anyone on this forum would do and disconnected the maf (again) - and the car drove much better. Another duff Maf then? Checked it with another 35€ Chinese one from eBay and either that was bad out the box too, or there was more to it.
i had gotten an old code reader obd thingamajigger to clear the srs fault it liked to throw and read the data streams for rpm and air mass+temp with no maf, Bosch and Chinese maf. It turned out that the air mass increased with rpm similarly between all the setups, but without the maf, the engine assumed the highest air mass, while the two mafs returned similar (smaller) values.
Important to see is that with the maf disconnected, the ecu supposes the air entering the maf was at ~-40’celsius, when it was actually about +10’. The ecu therefore assumes the air was about 25% more dense so it oughtabeen injecting 25% extra fuel. Does that tell me if my mafs are good or bad? I say it doesn’t.
You don’t necessarily need a new maf or use a synergy if your car runs better with the maf disconnected.
The engine will always perform better if you disconnect the maf while the temperature is greater than -40,
because it injects additional fuel that would only be appropriate in -40 degree weather. Not sure why it was chosen like that, maybe being setup for -40 helps it start or idle/run if it does get that cold. So, as running something like the synergy could get you into lots of trouble in Germany, for now my way to go will be keeping a maf plugged in when my wife has it, and when i feel like it or need power to tow, unplugging the maf for xy% power increase and for whatever reason better throttle response.
Let me know what your thoughts are!
