Cj7
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Joined: Aug 2019
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Cj7 I have a 83 cj7 with a 2003 5.3 on a 4l80e with a 4speed atlas tc. running 488 gears along with 42" tires.
still having trouble with the tranny not wanting to move into 4th gear even at 3000rpm.
does anyone have a segment i can download?
THanks
Randy
still having trouble with the tranny not wanting to move into 4th gear even at 3000rpm.
does anyone have a segment i can download?
THanks
Randy
TECH Regular
Joined: Dec 2011
Posts: 420
Likes: 115
What else can you tell about your situation?
What is your configuration of speed sensors?
Is your issue in high or low range or both?
Has it ever shifted into 4th? Do you know if the transmission and wiring are good?
Can you command a shift in HPTuners?
What MPHs are your shift points? Usually RPM is only one piece of the puzzle.
I guess backing up, what ECU and tuning method are you using?
What is your configuration of speed sensors?
Is your issue in high or low range or both?
Has it ever shifted into 4th? Do you know if the transmission and wiring are good?
Can you command a shift in HPTuners?
What MPHs are your shift points? Usually RPM is only one piece of the puzzle.
I guess backing up, what ECU and tuning method are you using?
Thread Starter
Registered User
Joined: Aug 2019
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Haggar, thank you for the reply!!!!!
i have all the wires hooked up correctly i believe along with both speed sensors. i have shift it with the computer. I do not have a speedo hooked up. 4 wheel low would no happen due to its to low.
it is a stock 2003 tahoe 5.3 ecu. i had my tuner down load a segment and it does what it needs however will not hit 4th gear on its own. as moving forward it will shift all gears however as speed increases at 3000 rpm the transmission wants to down shift if im on the throttle a little bit. if i back off it will stay in 3ard gear.
Thank you!!!!!
Randy
i have all the wires hooked up correctly i believe along with both speed sensors. i have shift it with the computer. I do not have a speedo hooked up. 4 wheel low would no happen due to its to low.
it is a stock 2003 tahoe 5.3 ecu. i had my tuner down load a segment and it does what it needs however will not hit 4th gear on its own. as moving forward it will shift all gears however as speed increases at 3000 rpm the transmission wants to down shift if im on the throttle a little bit. if i back off it will stay in 3ard gear.
Thank you!!!!!
Randy
TECH Regular
Joined: Dec 2011
Posts: 420
Likes: 115
What I would check first is the tables in ECU, and make sure that it's programmed with the right gear ratios and tire size/rpm per mile. If possible, try to verify with a GPS that the actual speed of the vehicle matches what the computer thinks it's doing.
There are 2 parameters needed for the shifts to occur: MPH and RPM.
Take a look through this thread, as a good starting point.
https://ls1tech.com/forums/automatic...tm-w-pics.html
You might try searching pirate4x4, there are many running similar combos there.
https://www.pirate4x4.com/forum/gene...-you-test.html
I know it's been discussed in the 5.3 Jeeps thread, but it's 270 pages long, so get a drink and snack before starting into that one:
https://www.pirate4x4.com/forum/jeep...jeeps-254.html
There are 2 parameters needed for the shifts to occur: MPH and RPM.
Take a look through this thread, as a good starting point.
https://ls1tech.com/forums/automatic...tm-w-pics.html
You might try searching pirate4x4, there are many running similar combos there.
https://www.pirate4x4.com/forum/gene...-you-test.html
I know it's been discussed in the 5.3 Jeeps thread, but it's 270 pages long, so get a drink and snack before starting into that one:
https://www.pirate4x4.com/forum/jeep...jeeps-254.html
