When I bought my truck it was shifting high I thought, about 2000-2500rpm. Then it just took longer for it to shift and now doesnt shift at all. Ive been working on it so its only had probably less the 20 miles put on it. The last time it shifted I had to wait until it was warmed up for a while and it was at high rpms.

The guy who had it before me was hard on it, he didnt pull anything just drove like a bat out of hell. He said the old man he got it from had a new transmission put in it 1 year before.

The fluid looks fine and doesnt smell, any ideas on whats wrong with it?

What truck? If it's the 92 in your sig then I would say the throttle position sensor has went out on you.

yes, the 92 in my sig is the problem, how do you check this sensor?

I'll see if I can do some reading up on this.

A standard run of the mill multi meter that reads voltage will do the trick. You want to check the output voltage on it. One wire will be a ground, one will be a 5 volt reference signal and the other will be the output. Make sure the ground to the sensor is good as well, if it loses ground it will read max throttle at all times. The TPS is a common problem on those though.

I played around with it a little. There is a grey, blue, and black wire. Black was ground, grey was 5v and the blue was from the sensor. I checked the blue wire and at idle it showed .50v at full throttle it showed 4.39v, it would be different anywhere in between like its probably supposed to. I would imagine this means the TPS is working or am I wrong?

Sounds like it's working. If that is the case then you need to get a scanner on it and see what it is reading from the ECM/TCM's standpoint.