Fuel Trims
Thread Starter
Burning Brakes
Joined: Aug 2003
Posts: 1,070
Likes: 9
From: MARRIOTTSVILLE MD
Fuel Trims
My LTFTs are normally between -1.5 and -6 when scanned using my
Predator. Last week when I filled the gas tank I noticed that my
LTFTs were -12 gradully changing to around -6 to -8 after driving
for 10 to 20 miles. The next day I drove another 20 miles and they
are back to normal. Is this a problem with my tune ? or is this something
that the car always does after a fill up ?
Thanks >>>>> INTHERED
Predator. Last week when I filled the gas tank I noticed that my
LTFTs were -12 gradully changing to around -6 to -8 after driving
for 10 to 20 miles. The next day I drove another 20 miles and they
are back to normal. Is this a problem with my tune ? or is this something
that the car always does after a fill up ?
Thanks >>>>> INTHERED
Safety Car
Joined: Aug 2000
Posts: 4,537
Likes: 84
From: St. Joseph MO
Cruise-In III Veteran
Cruise-In IV Veteran
If you were running the car cold earlier on, it could have added fuel early on to warm up. Then as it did, your LTFT's were made more and more negative until the computer was seeing more normalized operation(ie warming up, less stop-n-go traffic/maybe). Thats my guess maybe 
Racer
Joined: Mar 2004
Posts: 338
Likes: 0
From: Lancaster Ohio
I'm not sure how the predator logs. Does it show what fuel trim cell you're in? Do you log when it's cold each time? Was the car still in open loop maybe that time and in closed loop the other times you logged?
