hi i have a 94 F350 diesel with auto transmission. i have a few problems so here goes. first it idles at approx 500rpm, but when i rev it up over 1000rpm it goes from 500 to 0. i have replaced throttle sensor, just had gearbox completely overhauled and i am finding when i start driving in d mode it seems to drive off in first and second alright except when it hits d mode(drive) it seems to clutch slip, so i have to pull over. when i manually put it into first and then drive, and then go to second and then go to drive it appears to be okay???????
i have put it on the new snap on diagnostic test unit, it appeared to indicate there was a problem with the transmission control switch but confused. i really need help truck has been off the road for 9 months now, PLEASE I AM DESPERATE FOR HELP, THANKS

 

lets start with the basics...

Do you have the proper level of tranny fluid inside?
How many miles are on that transmission?
What was the code number that you pulled?

 

the gearbox has been completely rebuilt, less than 10 miles on it.
plenty of brand new fluid.
The gearbox people feel it is something electric, just dont know what.

 

we found the problem, finally fixed, we got the auto electrical people to have a look at the ECU and the whole ECU was corroded. we replaced it and its running fine now. i am now loving my truck again