Can anyone tell me the parameters I need to log to check to see if the car is over fueling?

Best

Simon
Car: 996 TT

 

Lambda bank 1/2 and STFT 1/2 as well as LTFT 1/2. Those are the basic fields to log.
Are you running a tune? If so, you could have lambda targets that are just too rich as well. Also check for vacuum leaks!

The DME can adjust +/- 25% ish. SO if you are running rich that means your STFT trims are unable to compensate beyond the correction threshold set in the ECU to keep the AFRs in check...which is based on the your target lambda values.

 

Yes running a tune uprated injectors 16/26 hybrids exhaust etc.

Datalogging is completely foreign to me so what does STFT stand for.

What values should I look for on the log ?

Should I do a 3rd gear pull or will i know at idle?
Whats the difference between a vacuum leak and a boost leak?

Still learning here!

 

NP
STFT - Short Term Fuel Trim ( Additive )
LTFT - Long Term Fuel Trim (multiplicative)


Values over 1.05 (this means that the DME is adding 5% correction to your injector pulsewidth)

Values of 1.10 = 10% correction to add fuel....and so on.

yea third gear pull should be fine...

vacuum leak = boost leak for the most part.

 

vacuum leak sucks air boost leak pushes air

 

^^^ right, if you have a vacuum you're probably going to have a boost leak.