AW4 not Shifting

Well for about the past week off and on. my jeep hasent wanted to shift for me it will hold the gears all the way up to 4,200rpm's and then shift, doesent matter how much gas i give it or anything. Sometimes it will shift just fine for me and then others it just wont.

What could it be? any suggestions would help.

-Matt-

Sounds like the fuel pressure module might be getting tired.

TPS almost positive