Originally Posted by maineah
The TPS is nothing more than variable resistor kind of like a volume control on a radio. Put your meter on ohms connect it to the center pin with one lead and the other on one to one of the other pins. The resistance readings are not as important as how well it changes it cannot drop out even slightly the readings must be smooth not jumpy at all. I don’t know how your throttle works on your truck if it’s a fly by wire you’ll have to remove the TPS and turn it with a screw driver. If there is a glitch it very well could be your problem because it sees no throttle position. FI repairs can get expensive fast if you just throw parts at it until it runs right.
Ok just tried doing that, and the resistance seem'd to be pretty smooth. With the dial on the "20k" ohm setting, it went from 3.3 closed throttle down to .86 at full throttle IIRC with no drops or glitches in between. Unplugged the front O2 sensor (before cat, trying to force open loop) and unhooked the battery for a couple mins, but that didn't change anything either.
After filling up with fuel, it runs MUCH better but you can still feel it hesitate when you give it gas from a stop, but it wont die. So so far these conditions have to be met in order for it to die when accelerating from a stop:
1. Warm weather (above 75-80)
2. Engine up to operating temp
3. 3/4 or less tank of gas
If any one of those conditions aren't met, it will run fine. However it's not hard to meet all those conditions, so it still happens quite often.
Is there a way to check the fuel pressure on the 2RZ? I looked but couldn't find a Schrader valve like most FI cars have on the fuel rail to connect to. Am I missing it or is there somewhere else to measure it from? I'm starting to think maybe fuel pump or MAF. I replaced the fuel filter last year, so that should be good still.
Thanks for all the help and suggestions so far though!