Had a p1233 code on my truck a month ago. I was told it was the fpdm so I went and got a new one and changed it. The old one was broke in half and corroded. My truck will get up to 30 mph and then if I give it gas, the engine revs up but it doesn't go any faster. I turn off the overdrive and it runs fine, but still want to fix this problem. There's no engine light anymore, but don't know what next to look at.

 

Definitely isn't your FPDM anymore. If your engine is revving, your FPDM is providing the needed power to the fuel pump to make it rev like you asked it to. Are you saying it's revving but going no faster than 30mph? As in, you can get to 30, then push the gas harder and the engine's RPMs pick up, but your speed doesn't increase at all unless you turn overdrive off, which case it does indeed go over 30? If that's the case, I fear you'll need to have your transmission checked out. Sounds like it could be trying to actually engage that overdrive gear and not having much luck with it. Any vibrations or shaking / shuddering when you rev it with overdrive turned on?

 

It goes up to 30 fine, but if I need to go any faster it will wind but not catch. With overdrive off it drives fine, but I feel it's hard on the engine. My brother said transmission, but I just wanted to see if anyone had this problem.

 

tranny...get it fixed now

 

Most deffinetly the tranny. I would get it fixed before it leaves you stranded!

 

Could be as simple as a bad TPS sensor, or as complicated as the transmission itself..
Any poor idle symptoms to go along with this issue? If so, I'd look into the TPS (throttle position sensor) first.