i have had the ms for a few months now and it seems like i have pulled 20% from the 15-17psi area and smaller amounts averywhere. i could tune it perfect and the car is very happy but a few weeks later it seems to be running rich or lean and needs to be retuned. is there a fix or does everyone have to deal with this?
#4071, "RE: why must i tune for weather changes?" In response to Reply # 0
During part throttle MS is using the O2 sensor to take out a little fuel or add some as the weather changes. When you go into open loop mode and the ECU no longer adjust your fuel you could start to run rich/lean if the weather has changed alot. So as it gets colder the intake temps should drop some and you may have to add some fuel at WOT.
#4074, "RE: why must i tune for weather changes?" In response to Reply # 1 Sep-20-08 06:56 AM by justins71
You need to alter your air charge temp correction values. The MS code notoriously over-corrects, so you'll see very rich in cooler weather and usually very lean in hot weather. Also make sure your sensors settings are correct, as this will intensify the effect. EasyTherm is the best way, IMO
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'95 GS w/ t3/t4b FMIC, diy piping & RFL BOV MS2-Extra Fuel&Spark 50 lb/hr Holley injectors w/ 1:1 RRFPR JE 8.8:1 dish w/ Hastings Rings Eagle Rods w/ ARP bolts ARP Head studs Mild port/polish head 3" custom DP/cat section, 3" PIT catback dual MBC - 12 psi / 20psi
#4077, "RE: why must i tune for weather changes?" In response to Reply # 2
i don't have an o2 sensor wired to the ms and ego has no athority. when it gets warmer it get rich and when i go to lower elevations it gets crazy rich. my iat sensor died and sinse then it seems to be very consistant. is the air charge settings the really confusing ones? i think i was checkin all that out and decided to leave it alone cause the notes told me to. lol
