1-2 Hits Rev with logs
08-13-2008, 04:00 PM
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1-2 Hits Rev with logs Rebuilt 4L60E in a 2000 Z28 with a Transgo kit and Yank 3600. 1-2 Hits the limiter a few times before the shift. Its driving me crazy. I pulled the trans and the 2-4 band and new drum still looked awsome. Everything inside looks great and all other up shifts and down shifts are great. I build lots of 4L60e trans and never had this problem or I can fix it quick. I have had bigger converters with no problems.
The 1-2 MPH is set at 37
The 1-2 RPM is set at 5800
Revlimiter set at 6700
I have two WOT logs
In the first log the scanner shows that the current gear changed from 1-2 at 6678RPM @ 48MPH and finished the shift at 6778RPM @ 48MPH The 6678RPM is in the frame that the O2 sensor show a drop from hitting the Revlimiter.
In the secound log the scanner shows the current gear change from 1-2 at 5766 @ 39, thats my 5800 shift RPM. The very next frame shows current gear as first not secound and then the car keeps pulling untill 6548 @ 46mph. The shift finishes at 4749 @49 MPH. Again the 1-2 shift happens at the same frame in the log that it hits the limiter.
My 2-3 shifts never hit the limiter but they show a lot of the same. They show the current gear shifting from 2-3 when I want but calculated gear is still 2nd and in the next frame its back in 2nd for current gear. It will then keep climbing in RPM's up to about 6500 and shift just before hitting the limiter.
Basically on the log, looking frame by frame I have a current gear of 1 on and then at the programmed shift time point the next log frame will show 2 and then the next log frame will show 1 again. The whole time the calculated gear is 1 and the car keeps climbing untill it hits the revlimiter. At that same frame as the limiter the car shifts to 2nd and all is well.
I feel nothing weird during any of this and the car shifts great other thean wot 1-2. All MPH are met and I have lowered and raised the limiter with no change. It just keeps reving untill it hits the limiter and then shifts. Around .4 shift times and 240-260 psi pressure.
Any suggestions, that have worked for other people.
The 1-2 MPH is set at 37
The 1-2 RPM is set at 5800
Revlimiter set at 6700
I have two WOT logs
In the first log the scanner shows that the current gear changed from 1-2 at 6678RPM @ 48MPH and finished the shift at 6778RPM @ 48MPH The 6678RPM is in the frame that the O2 sensor show a drop from hitting the Revlimiter.
In the secound log the scanner shows the current gear change from 1-2 at 5766 @ 39, thats my 5800 shift RPM. The very next frame shows current gear as first not secound and then the car keeps pulling untill 6548 @ 46mph. The shift finishes at 4749 @49 MPH. Again the 1-2 shift happens at the same frame in the log that it hits the limiter.
My 2-3 shifts never hit the limiter but they show a lot of the same. They show the current gear shifting from 2-3 when I want but calculated gear is still 2nd and in the next frame its back in 2nd for current gear. It will then keep climbing in RPM's up to about 6500 and shift just before hitting the limiter.
Basically on the log, looking frame by frame I have a current gear of 1 on and then at the programmed shift time point the next log frame will show 2 and then the next log frame will show 1 again. The whole time the calculated gear is 1 and the car keeps climbing untill it hits the revlimiter. At that same frame as the limiter the car shifts to 2nd and all is well.
I feel nothing weird during any of this and the car shifts great other thean wot 1-2. All MPH are met and I have lowered and raised the limiter with no change. It just keeps reving untill it hits the limiter and then shifts. Around .4 shift times and 240-260 psi pressure.
Any suggestions, that have worked for other people.
08-13-2008, 04:47 PM
#2
Is that 240-260 pressure measured with a gauge or calculated with the PCM thats IMO to high 220-230 should be max WOT line pressure.
To much line its possible your flooding the solenoids but again it could be in the tuning its hard to say.
If the lines not to high then you may try something a guy called me and told me worked on his he went to where it says kick down and shows % of TPS for the 3-2 and 2-1 down shift and raised the percentage in his case to max but if you have a tuner it might be worth a try.
Also bear in mind you cannot set shift points based on MPH alone you must meet MPH and RPM settings for the shift point.
Might fair better posting this in the tuning section also
To much line its possible your flooding the solenoids but again it could be in the tuning its hard to say.
If the lines not to high then you may try something a guy called me and told me worked on his he went to where it says kick down and shows % of TPS for the 3-2 and 2-1 down shift and raised the percentage in his case to max but if you have a tuner it might be worth a try.
Also bear in mind you cannot set shift points based on MPH alone you must meet MPH and RPM settings for the shift point.
Might fair better posting this in the tuning section also
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