[Chevy 350 Fan]

[QUOTE=Gromit;7450387]Idle is way too high in my opinion - need to do whatever it takes to fix that first.. Stock idle is more like 580 to 650 for my TH350 in a 290 HP 350 Cubic Inch V8 with a stock Corvette HP cam (but sounds like you have even more HP than that) - But at least your extreme high idle is affecting your vacuum levels which is then affecting your trans valve body logic. 1500 RPM is well into the jets and the butterflies are completely out of the idle circuit, so vaccum is lower than it should be at idle. =QUOTE]

Then what happens when you started it on a cold morning with the choke and high idle activated and put it in gear without hitting the gas a little to take high idle off? High idle is like 1500rpm