I recently helped a buddy of mine swap a 1999 3.4 into his 1993 x-cab truck... we got the motor in and all the wiring done and it runs but will not rev.... it idles pretty good except it seems to load up some but as soon as you stomp on the throttle it just falls on its face..... we have tried replacing the TPS with no change... using the directions in the chilton manual I have tried to check the MAF sensor and I can not get a voltage reading off it so I need to check with someone that I am doing the test properly ( will call toyota tomorrow).... I was just looking to see if anyone has run into this type off issue before and what it was.....

 

Check the power supply wire that goes to all your sensors. I just had the same problem. I think that mine was a white wire with a blue stripe, and it needs to be connected to you EFI relay power.

 

I know this is an old post but if any one is looking for this answer in the future now it is here.