Need help!!!
Need help!!! Hey guys i have a 95 z28 camaro with a performabuilt level 2 trans and a 3800 converter.
At WOT the car gets through first and second just fine but when it shifts into 3rd it shifts in and then shifts straight into fourth without pulling through 3rd.
I did get a mail order tune from madz28 and the shiftpoints were set at 6k.
so is this a tuning issue or somthing els?
Thanks guys
At WOT the car gets through first and second just fine but when it shifts into 3rd it shifts in and then shifts straight into fourth without pulling through 3rd.
I did get a mail order tune from madz28 and the shiftpoints were set at 6k.
so is this a tuning issue or somthing els?
Thanks guys
Well the fact that it shift to 4th tells you the 3-4 3-4 clutch set is good and the trans is mechanically sound.
Could be tuning could be a sensor. Have you dont any work with the intake, cam or throttle body recently?
The 4l60e cannot decide to shift on its own as its totally at the mercy of the PCM so I would says in in one of the areas I mention above.
Could be tuning could be a sensor. Have you dont any work with the intake, cam or throttle body recently?
The 4l60e cannot decide to shift on its own as its totally at the mercy of the PCM so I would says in in one of the areas I mention above.
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Teching In
Joined: Apr 2010
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Did you upload the tune and it started happening, or was it working fine with the tune then just started out of the blue? It could be a few things. The TPS sensor may be failing intermitantly. Are you sure its shifting into 4th or is the converter just locking up in 3rd?
Teching In
Joined: Apr 2010
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I would say its something with the tune. The only way to know if its the torque converter clutch or shifting into 4th is to get a scanner or tech2 and drive the vehicle while watching the data and see if the tcc is commanded on when the shift occures or if 4th gear is commanded when it shifts. Or you could dissable the tcc in 3rd gear by changing the tune and go from there. One other thing that would help is when it shifts does the rpm drop alot or do you just feel it shift gears and the rpms stay close?
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I will try and find the tune later today. But i talked to madz28 and he said he didnt change the shift points only the rev limiter.
Anyways heres a vid i took of it. its at the top of second in the start.
http://www.youtube.com/watch?v=_qQeRBDf99Q
Anyways heres a vid i took of it. its at the top of second in the start.
http://www.youtube.com/watch?v=_qQeRBDf99Q
Teching In
Joined: Apr 2010
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Thanks for the video. To be honest with you its really hard to determine just watching the video. Usually with a stall when a vehicle shifts gears it doesnt change rpm very much. But when the tcc locks up it is a big change. That sounds like a big change but with that stall it should be a bigger change. It doesnt sound like the tcc is locking up. seeing the tune would help or some actual data from the car. You might have to change the shift timing in the tune to fix it.
Last edited by boostedLSX; Jan 25, 2011 at 10:19 PM.
I'm about 90% positive its locking up. i can feel it when it first shifts into third and then right into fourth. there is a huge feel difference. just like when it locks up driving on the freeeway normally.
and my tuner said he didnt touch the shift points. So what should i change them to?
and im still looking for the tune
and my tuner said he didnt touch the shift points. So what should i change them to?
and im still looking for the tune
Teching In
Joined: Apr 2010
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I believe that he didnt touch anything with the shift point. Im not trying to pin this on him at all but sometimes when you put a stall convert on a car it throws things off because the big jump in rpms versus factory settings. What i ment when i said it doesnt sound like its locking up is it sounds like the trans is shifting into 4th gear, not locking up the tcc in 3rd gear. I could be wrong but thats what it sounds like from the video. This might have to be a trial and error thing. You'll have to call your tuner up and have him ride with you in the car. Adjust the trans shift point. Take it for a spin again and see what happens. If it still happens you"ll have to adjust some more and keep going until its dialed in.