4L60E no upshift
Thread Starter
Teching In
Joined: Aug 2005
Posts: 1
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4L60E no upshift Vehicle is a '99 Tahoe (I know its not a LS1, but the PCM seems to have similar variables and you guys look to be pretty knowledgeable on this stuff). My solution to the pos CPI injection was to yank it and put a carb on it. Motor runs great. Only sensors missing are inlet air temp, and MAF. No codes other than MAF and IAT.
I originally had the TPS wrong and couldn't get the TCC to lock up and it would hold all the gears too long. I fixed the TPS so that it correctly indicates the amount of throttle opening, now its holding 1st until 3000rpm with like 10% throttle and then only shifting when I let off a little. Haven't tried WOT. Seems like it might be better with 50%. I've tried lowering my 1-2 shift point to 10mph across the board and still holds 1st as long as I'm on the gas.
It feels like it has a ton more torque, especially down low. And when I coaxed it up into 4th on the freeway, 75mph unlocked was 3000rpm where before it would be more like 2400-2500.
Is my trans toast? or is there just no way this is going to work without a stand alone trans controller.
I originally had the TPS wrong and couldn't get the TCC to lock up and it would hold all the gears too long. I fixed the TPS so that it correctly indicates the amount of throttle opening, now its holding 1st until 3000rpm with like 10% throttle and then only shifting when I let off a little. Haven't tried WOT. Seems like it might be better with 50%. I've tried lowering my 1-2 shift point to 10mph across the board and still holds 1st as long as I'm on the gas.
It feels like it has a ton more torque, especially down low. And when I coaxed it up into 4th on the freeway, 75mph unlocked was 3000rpm where before it would be more like 2400-2500.
Is my trans toast? or is there just no way this is going to work without a stand alone trans controller.
