98 camaro v6 3.8l 4 speed automatic.
When siding from 1st to second it won't shift until 4000rpms. Same for second to 3rd. Won't even shift into 4th manually auto. Transmission reads a quarter inch high for check when hot mark. Could that be problem or much worse?

 

probley not ,could be you need trans flush an filter or the linkage adjustment ? have you ever done one ? whats the miles? do you manually shift your auto trans ,so you said it wont shift manualy ,but will if you just put in drive ,it could be worse but I don't think the fluid being a bit high plays any role , you may want to have someone look at it? do you drive it hard ,?do you down shift to slow down

 

I drive it normally, no I haven't flushed out changed filter. I've neveradjusted a linkage. Do you have directions?

 

yes you probly should have the fluid and filter changed,,,, lol. could try reseting the system computers. unhook both cables to the battery and hold them together for about a minute and hook them back up. see what happens. it will take a couple of runs for computer to set itself to the engine so it could idle strange the first run.

 

got it straight it was actually a bad throttle position sensor.