Towing???

2001, F-150, Super Crew, Lariat, 5.4 Liter, unknown tranny. My pick-up has always had a problem maintaining RPMs if towing up long inclines. At highway speeds 3rd becomes too high (slowing due to low power) and 2nd is too low (high RPMs), same for lower speeds, 2nd is too high and 1st is too low. The passing gear kicks in and I don't tow with the over drive engaged. Any suggestions?

Let me add some info. it is an automatic tranny, three speed, I don't know the gear ratios. It is also four wheel drive. Runs fine other wise.

The engine, if running right, has enough power for most towing tasks. Your culprit then most likely is either the transmission isn't geared correctly for towing or the rear end is the wrong gearing for towing, or a combination of the two. Some trucks are bought by utility companies from the factory with specs that aren't conducive to highway driving, with a 3 speed transmission and not 4 speed, I would guess that is your case.

The 5.4 is seriously underpowered for what it is. I used to drive a 5.4 F250 for work and occasionally had to tow a 20' trailer with various things on it. The thing struggled to get out of its own way even without the trailer behind it.

Are there any adjustments to the computer, or other, that will increase the power?