Syptoms:
Well under normal driving usually at low rpm's my car will sputter. It almost feels like someone is pushing in the clutch and quickly releasing it over and over for a short amount of time, only for like about a few secs. I have an eg with an ls and this problem has slowly gotten worse in the past year. I have a vafc which I have monitored my tps voltage while under these moments of surges. I noticed that the tps would jump up and down between .2 and .5 volts when I gradually acellerate. I also noticed that at idle the tps voltage is around .395-.385 and under full throttle it only goes up to 4.3.

I thought that a good working tps should be .5 at idle and 4.5 at full throttle. Is that correct? If so would this be my problem? I do have a new cap, rotor, and wires. Maybe Im looking in the wrong place for my problem, and its not the tps. Anyone have similar experieces or have an idea of what is wrong? I do get a cel once in awhile but I havent pulled the code yet. I usually just turn the car off and start it again and it goes away. Does anyone think that it could be the wiring on the vafc? The only thing that I can figure that is wrong is tps but I could be wrong and I dont want to spend to much time messing with the tps and vafc wiring if it is not the problem. Can anyone chime in and help me out? Thanks in advance

 

I dont think its your TPS, I think if you check the code that will give you a good start. Also replace your plugs, wires, cap and rotor.

 

Im having the exact problem,i cant get the tps calibrated right either because of the jumping voltage issue,mine will idle ok @ 850 rpms,then after about 30 seconds the idle will drop to about 650 rpms,and spitin,and sputtering.i have a vafc wired up,and the tps voltage is not the same as at the ecu.its about .5 volts higher than at the voltmeter.plus I cant get 4.5v with the throttle open.i get 4.93v no matter where I set the tps at.any suggestions?

 

check the map sensor