Injector swap question
05-03-2014, 10:18 PM
#1
Junior Member
Thread Starter
Join Date: Feb 2014
Location: Pikeville, KY
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L
Injector swap question
Ive got a 98 xj and swapped to the 703s today. Jeep is running smoothly but I have yet to reset the PCM. Is it necessary to reset the memory or will it learn the new fuel trims anyway?
05-03-2014, 11:35 PM
#2
Seasoned Member
Join Date: Mar 2014
Location: Los Angeles
Posts: 352
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
Hmm I forgot to reset them too...it's so simple to I forgot how something. Like hold your nose, turn off the headlights, stand with your feet at a 45 degree angle and do a back flip. Lol jk I forgot how do u know I'm lazy to look it up.
05-03-2014, 11:40 PM
#3
Herp Derp Jerp
Join Date: Nov 2011
Location: Parham, ON
Posts: 18,251
Likes: 0
Received 12 Likes
on
11 Posts
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
The process dumps trained data for long term fuel trim. LTFT data is based on the last twenty warm-up cycles, defined as periods that the engine reached a minimum of 180°F.
If you reset it you lose your last 20 startups and go back to default settings. If you don't, your PCM adjusts long term trim over the next 20 warm-ups. It will still base Short Term Fuel Trim off of immediate input like MAP and O2 sensors.
It is not necessary unless you had problems before or you are having problems now. It also dumps your trip odometer and saved radio stations, which is a real pain in the ***.
If you reset it you lose your last 20 startups and go back to default settings. If you don't, your PCM adjusts long term trim over the next 20 warm-ups. It will still base Short Term Fuel Trim off of immediate input like MAP and O2 sensors.
It is not necessary unless you had problems before or you are having problems now. It also dumps your trip odometer and saved radio stations, which is a real pain in the ***.
05-03-2014, 11:50 PM
#4
Seasoned Member
Join Date: Mar 2014
Location: Los Angeles
Posts: 352
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
The process dumps trained data for long term fuel trim. LTFT data is based on the last twenty warm-up cycles, defined as periods that the engine reached a minimum of 180°F.
If you reset it you lose your last 20 startups and go back to default settings. If you don't, your PCM adjusts long term trim over the next 20 warm-ups. It will still base Short Term Fuel Trim off of immediate input like MAP and O2 sensors.
It is not necessary unless you had problems before or you are having problems now. It also dumps your trip odometer and saved radio stations, which is a real pain in the ***.
If you reset it you lose your last 20 startups and go back to default settings. If you don't, your PCM adjusts long term trim over the next 20 warm-ups. It will still base Short Term Fuel Trim off of immediate input like MAP and O2 sensors.
It is not necessary unless you had problems before or you are having problems now. It also dumps your trip odometer and saved radio stations, which is a real pain in the ***.
Thread
Thread Starter
Forum
Replies
Last Post
Tcq192
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
7
10-23-2015 09:25 AM
CherokeeHoonigan
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
4
09-04-2015 12:47 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)