hally

I was in the mountains last week very cold, well about zero degrees C. Anyway i noticed on part throttle say 3500rpm where boost was starting to build my wideband showed numbers in the 15's and engine stumbled. (should have logged it ah well) The car had been running for about 5mins so had warmed up to some degree. Looking back i remember experiencing the same condition a year ago when i last went to the snow.
So is my intake temp sensor not working properly in the cold conditions or do i need to make some adjustments to my PT map so that the closed loop operation doesnt need to work so hard? Warmer conditions A/F always dithers around 14.7 without any probs.

z3bra

Just a thought, could the low temperature cause your car to experience an overboost condition?

If you've got an MBC set for 15 psi at say 25-30 C and you're driving in 0 C weather, it's going to be making more boost than you have it set for because of the colder denser air that's being ingested as well as the intercooler working more efficiently at the lower temperature.

hally

no overboost in this case, would have been no more than 10psi, wasn't getting into the throttle too much. I'm with you on the colder, denser air, but this is what the intake air temp should be allowing the DME to compenstate for by adding fuel..?..