1992 Toyota pickup 22re
The truck starts and is real strong when cold. Once the temperature comes up (after ~2 mins of driving) it runs great until I put my foot down to about 1/3 throttle, then the more I press the throttle, the less power I have until my foot goes right to the floor, then I have full power again. It makes makes more noise and sounds like the engine is working harder as I give it more gas, but I have less power the more throttle I give it. The only things I can think of are either the TPS or the VAF meter. I tested the TPS and it is good, and I will test the VAF meter and post the results when I do.

 

Codes? Timing?

 

So I tested the VAF meter according to these specs: http://bit.ly/1nntiTN The only abnormality was E2 - Vs when it was closed. There was about 700 ohms of resistance between those two terminals instead of the 20 - 400 ohms that it should have been. Does it make sense that this would account for the issue?

 

No error codes, and I checked the ignition timing and it was fine.

 

What Transmission Auto or Manual??

It sounds like your transmission or clutch might be slipping.

Does your truck have a tach and what is it showing while doing this compared to the speedometer??

 

Check for vacuum leaks as well.