gijoecam
Village Idiot
- Joined
- May 31, 1999
- Messages
- 8,336
- Reaction score
- 17
- City, State
- Trenton, MI
- Year, Model & Trim Level
- 98 ExSport, '00 F-150
Creager said:i think all that information actaully supports the TPS mod. if your moving you lowest voltage reading to .96, then its definatly going to start learning .96v compared to .95v. Since this mod is really not about performance but "how far you physically have to push the gas petal"
JamesT initiated it so you dont actually have to push the gas petal as far down as you usually do to get the same effect.
I would tend to agree with that argument if I hadn't stumbled upon this earlier this morning (accent added):
Throttle Position Sensor
The throttle position (TP) sensor (Figure 42) is a rotary potentiometer that provides a signal to the PCM that is linearly proportional to the throttle plate/shaft position. The sensor housing has a three-blade electrical connector that may be gold plated. The gold plating increases corrosion resistance on terminals and increases connector durability. The TP sensor is mounted on the throttle body. As the TP sensor is rotated by the throttle shaft, four operating conditions are determined by the PCM from the TP. Those conditions are closed throttle (includes idle or deceleration), part throttle (includes cruise or moderate acceleration), wide open throttle (includes maximum acceleration or de-choke on crank), and throttle angle rate.
From what I gather from the info in the Powertrain Control information, the actual voltage that the TPS outputs is irrelevent. It sees the lowest voltage after startup and sets that as closed throttle/idle. Then if you crack the throttle (i.e. raise the output) it sees part throttle. If the voltage gets above 4, it sees WOT. The PCM also measures the rate of change so it can determine if you're just gently accelerating, or if you are calling for a transmission kick-down to pass.
Maybe I'm mis-interpreting the info in the service manual?
From a design standpoint, the ratch voltage adjustment compensates for the slight variations everyone experiences right from the start from vehicle to vehicle. Different installation methods, slight differences from one TPS to another or one brand to another should be compensated for by the PCM by the way it interprets the signal.
I dunno.....
-Joe