Quick Datalogger fuel trims question

[spoolintsi97]

If the numbers are positive its lean and if they are negative its rich correct?

 

[CanadianTSi]

Correct.

 

[spoolintsi97]

Thats what i always thought but I was reading something today about tuning and I started to second guess myself Thanks for the info.

 

[spoolintsi97]

My car has never set any LTFT's since a year ago when i bought the logger and never thought anything of it, is this normal because I want to tune the car right now instead of having it just drivable on the maft and afc. Also my car failed emissions last year and they thought it was because of the ecu resetting itself all the time the car is shut off do thse problems seem to be caused by each other. I've just read something about some ecu going bad has anyone else had this problem.

 

[CanadianTSi]

Your car also has to reach a certain temp to update the trims (180 i think?) so if your T-stat in stuck open and your car never fully warms up that could cause it.

 

[spoolintsi97]

I replaced the thermastat already and my logger will read temps into the 200's soemtimes. My STFT works fine I am just wonding if i should by a new ecu or if i should just tune with the one I Have.

 

[spoolintsi97]

Well I figured out why my car was not making any ltft's it was a faulty maft translator. So instead of buying a new translator for $200 I bought a barometric pressure sensor from ebay for $2.00 and mounted it in my dejon intake. The sensor is an AC Delco and is for an oldsmobile 88 and a few other cars. The sensor works great and my car is now properly tuned for the fuel trims, as soon as I get my Wideband in i will re-tune the SAFC hi throttle to the best settings.

 

[siceclipse]

good shit