I've got a 1995 5.0L with an automatic transmission. I am getting a delayed shift from 1st to 2nd gear as I have to decelerate in order to get the truck to actually shift. Once it is out of 1st gear it seems to run fine and shifts through the other gears without issue. Once I get to 20-25 mph, the rpms seems pretty high, but once I back off the accelerator, the transmission shifts to the next gear and runs good. Hopefully it's nothing serious, but I am not certain.

 

Did you check the trans fluid?

Proper way of checking Auto tranny fluid:
With engine running (warmed up is best)
Shift all the way down into low gear, count 3 seconds, shift up one gear count 3 seconds, go through each gear waiting 3 seconds (including N and R )
Put back in park, Insert CLEAN dipstick, then remove. Fluid should be in crosshatched area. From LOW line to FULL line is 1pint (1/2 quart.) add fluid as needed. ENGINE SHOULD BE RUNNING THE HOLE TIME

IF fluid is over filled, best way to fix it is to remove trans pan to drain old fluid (should replace filter at same time).

If the fluid is full and you are still having a problem, try changing the trans filter.

 

TPS sensor? computer unsure of throttle, delaying shift?

 

Thanks for the advice. I recently had the transmission fluid changed, but have not checked the level since the problem started. I'll give it a shot and see what happens.