I am completely confused.

When external temperature going down below +5C, my d2 start moving like somebody always just keep gas pedal little more pressed then me . So car speed is growing up little faster ... i need to push brakes more frequently .. and fuel leaks with amazing speed (about 30-32 litres per 100km instead usual 23-25)

When car at idle (no matter on parking or i just push breaks pedal) - nothing unusual. RPM at +-660, no anormal fuel consumption (checks by T4 book), etc ...

When car moving from hot garage, sometime all ok (i think, till something are cooling down) but after sometime all thing back ...

I thik its something like external temperature sensor is broken and send to ECU wrong data, but I cannot find this "sensor" related to ECU, only for AC ...

whats going wrong in my case?

SOLVED: main problem was in catalytic convertors between first and second lambda zonds. When i connect obd loggers and drive, some signals (like O2 sensor voltage) start looking very crazy (on idle all ok). I change lambda sensors. Nothing happens. As i understand by logs, ECU try to adapt and opens fuel sprayer for little more time, when more time again and so on. So i reach "gas pedal down" effect with big fuel consumption (at top i reach 30 litres per 100km instead 23-25). After that i got P0171 & P1171 (O2 sensor bad value) error codes. I clean codes and continue driving. At idle i reach many P030x (misfire) errors and big vibrating from engine: by logs, ECU just flood sparking plugs with fuel.

So i came to service and replace catalytic to flame damper and set some small electric to trick the ecu (because now i have only 2 lambda insead of 4).

Result: all errors code are gone, very (VERY) silent engine and big decrease of fuel consumption even on idle (before was 2,1-2,2 litres per hour, after 1,7-1,8 by obdII diagnostic). fuel consumption when driving is still calculating

PS sorry for my pure english

 

You have done most of the diagnostics. The D1 has a separate IAT (Incoming Air Temp) sensor at air filter box, the D2 incorporates it in the MAF unit. Pages attached from RAVE. The IAT is a value sent to ECM and also to the code scanner plug under the dash. So if you plug in your data reading code scanner, should be able to see this numbe, and see if it makes sense. Wehn mine is unplugged it tells the ECM that the temp is -40F, and I imagine that changes the mixture quite a bit. Pages from RAVE attached.

Here's a pix of a scanner readout, this was very high because I was overheating slightly, at idle for a long time testing, on 100 F summer day, and my IAT is just under the hood because I have a cone air filter. So that is the underhood temp. Should be the local temp when cold start, and should warm up. Should not stay cold.

Attached pix of connector, pin 1, slate/green , is IAT signal.

 

Thanks, i compare IAT data out with real data, because no error codes appears ...

 

Yes, so if it is 44 degrees outside where you park, IAT should not be say -25 F.

 

And it could be that someone has it in Sport mode, which would change shift points...., or you are not going into 4th gear.

 

Just connect computer thru OBDII. IAT data are correct ;(

 

No sport mode, usual driving ... just outside temperature changing ...

 

Well, it will run mixture up (increase pulse width to electronic injectors) to keep air/fuel mix in an ideal range. If no codes, it is happy. All of that kind of stuff is supervised by the ECM multiple times per second.

Air pressure in tires off causing decrease in mpg as well?

 

Yes, i know about it ... may be ECU is happy, but me is no ... i do not understand, why EDU thinks what i need more power just because street temp is going down ...

Air pressure in tires is ok too ...

 

Take a look at how the air fuel mix is regulated. Might be a small vac leak that is small enough to have an impact and not enough to move the magic spot outside the limits of the "fra", and has not thrown codes.