Tps Vs Iac
- Thread starter blksc
- Start date
Katoom
Registered User
TPS = Throttle position sensor. It's basically a rheostat, similar to a volume knob on a stereo. As you push the gas pedal, the throttle plate opens. The TPS is attatched to the plate and rotates as well. The TPS regulates either voltage or resistance (I'm not sure which) and tells the EEC engine computer exactly how far you have the gas pedal pushed. The EEC uses this info to calculate how much fuel to feed the engine.
IAC = Idle air controller. When your car is idling, the throttle body plate is closed. The engine cannot get any air. There is a port on either side of the throttle body.
Both ports mate up to the IAC. This device regulates the amount of air getting to the engine tio keep it idling properly. For example, when your A/C compressor turns on, there's more load, therefore the IAC would let more air pass to the engine to keep it running.
My IAC broke last weekend, it stuck wide open, therefore the car was idling at 2200RPM. I would also imagine that they could fail closed as well, causing the car to not idle at all.
TPS. If it goes intermittent, like a staticy old volume knob on a radio, it could confuse the computer as to how far the throttle is open, and really screw up the fuel/air mixture on the engine. Hesitation is a common problem when these fail.
IAC = Idle air controller. When your car is idling, the throttle body plate is closed. The engine cannot get any air. There is a port on either side of the throttle body.
Both ports mate up to the IAC. This device regulates the amount of air getting to the engine tio keep it idling properly. For example, when your A/C compressor turns on, there's more load, therefore the IAC would let more air pass to the engine to keep it running.
My IAC broke last weekend, it stuck wide open, therefore the car was idling at 2200RPM. I would also imagine that they could fail closed as well, causing the car to not idle at all.
TPS. If it goes intermittent, like a staticy old volume knob on a radio, it could confuse the computer as to how far the throttle is open, and really screw up the fuel/air mixture on the engine. Hesitation is a common problem when these fail.