low med high/ short term long term?

[DSMstatus]

ok, i have a 97 gst, ive been reading about fuel trims and i have found a lot of stuff about low mediun and high fuel trims but my scanner/logger shows short term and long term fuel trims, whats the difference?

 

[steve]

Whats the difference?

The difference is 1G's have low/mid/high and 2G's have short and long term.

Steve

 

[impuresoul2k3]

Long Term Trim:
A learned value over time which changes gradually in response to conditions such as fuel oxygen content, engine wear, air leaks, variation in fuel pressure, altitude and so on. Long term trim is a component of what Toyota technical literature refers to as the "Basic Injection Duration". Basic Injection Duration data is stored in a nonvolatile RAM and is not erased even when the engine is shut down. This information is used during warm up and wide open throttle conditions.

Short Term Trim:
An instantaneous correction value determined from the oxygen sensor readings. Under normal conditions it cycles rapidly around the 0 percent correction value and is only functional during closed loop operation. Short term trim is a component of the "Corrected Injection Duration". Corrected Injection Duration is used only during closed loop operation and not during open loop conditions. When Short Term trim exceeds plus or minus 10 percent for too long, the Long Term trim begins shifting, changing the Basic Injection Duration to bring the Short term trim back within the plus or minus 10 percent range. Short term trim can vary as much as plus or minus 20 percent, but the above correction mechanism works to keep it within plus or minus 10 percent.

Low/Medium/High
Fuel Trim settings for idle, cruising, faster cruising

http://www.4x4wire.com/toyota/4Runner/tech/OBDII_ECU/
http://members.shaw.ca/costall/1000Q/Frameless/answers-SAFC.htm

 

[DSMstatus]

that helps me very much, now is a long term of 7 too much fuel, for some reason the short term is seeing a lean condition so it is making the long term cycle between 0 to 7 during driving which means its dumping fuel into the engine, hence the smoke puffs from the tail pipe and rich fuel smell and the mid range hesitation. but i cant seem to find the problem that is making it rich like that, got any ideas?

 

[DSMstatus]

i forgot to add, along with the problems in my previous post, im getting 10 miles per gallon., infact, this all started after i did my prothane motormounts, got any ideas?

 

[DSMstatus]

just did some tests, the o2 sensor tested good and there are no boost leaks, what else?

 

[DSMstatus]

anybody?