I purchased a 93 F150 4.9 auto for a weekend use truck knowing that it had some trans issues. (O/d light won't turn off and no 2-3 upshift once warmed up.) I figured I'd take it to a trans shop, fix it and move on. Not so easy. 1st trans shop says they think it might need a new trans and when I came to pick it up the employees were all offering to purchase the truck. Seemed sketchy so I went to another shop. 2nd shop says solenoid pack shorted out. No problem... change it. Still the same. They found that the pcm wasn't communicating any live data with their scan tool and suggested I replace it. Replaced. Now the o/d light turns on and off. But still no 3rd or 4th gear once warmed up. I did notice that when I do have 3rd/4th it will only go into them at low rpm. Any small increase in RPM causes immediate down shift. This made me feel like it could be a tps issue. Changed that (properly clocked) no change. Im at a loss. If anyone has a suggestion I'd certainly appreciate it. Im ready to put a bullet in this truck!

 

See if you can have the vehicle checked for any trans codes. That should help provide some direction.
There could be a problem with the overdrive system. Depending on what code(s) obtained , you might need to drop the pan and look for possible broken overdrive servo parts.
Possible problem with trans control module.

 

You likely have a stored code. Staying in second gear is being in a "limp mode" indicating an issue and a code being set.
Don't overlook a wiring issue between the tranny and PCM.

 

I appreciate the feedback guys. I found 2 stored codes. 334 which I believe is egr related???? And 628 which I know is a converter slippage code.

 

From my recollection , those EGR sensors were problematic. Just get a new one from FORD and replace it.
You might want to soak with PB Blaster , the three little screws that hold the sensor on to the valve assy. They were easy to wring off if not careful. If you notice it starts to feel funny while trying to remove the sensor screws , get another valve assy. before you windup with no sensor mounting.

 

I replaced the egr and sensor (aside from removing the plenum to drill the rusted studs out, it was a breeze). I attempted to clear the codes by disconnecting the diag jumper while flashing but it didn't erase the codes. Either way... drove the truck again and checked codes. Still have the converter slippage code (628). I dont believe this would cause a no 2-3 upshift though. Any suggestions fellas? When the truck is cold, it runs through the gears well. After 5-10 mins of driving it starts acting up. Won't shift to 3rd unless you let off the gas. Then it won't stay in 3rd. Constantly down shifting to 2nd. Then it doesn't want to shift to 2nd unless I let off the gas and it slams into gear. Let it cool down and the cycle starts all over again. O/d light not flashing and will turn on or off the entire time by pushing the button. I have some cold brew and a cigar for someone to help with this. Or money. I'd pay to make this headache disappear

 

I pulled the harness today. The wires at the solenoid pack plug were a little burnt but I didn't see any shorts. I replaced the plug and wires. Still no difference. Drives great for 5 mins then it starts back to 1st and 2nd gear only. The only trans related code is the converter slippage code but it's stored and not current. Has a 334 that's current. Any other thoughts?

 

Any body have any thoughts on this?