What have you tried? How much have you driven it since replacing the sensor? Did you get a diagnostic fault code that led you to the throttle position sensor?
By replacing the throttle position sensor, you may have inserted a new problem that didn't exist before. If the voltage on the TPS at idle is higher now than with the old sensor, the engine computer is never going to see "minimum throttle" that it has memorized. It will not try to control idle speed until it knows your foot is off the gas pedal, and it knows that by the TPS voltage.
Minimum throttle is also lost from memory if the battery is disconnected or run dead. The engine will not stay running at idle unless you hold the gas pedal down 1/4". To relearn minimum throttle, drive at highway speed, then coast for at least seven seconds without touching the brake or gas pedals. If this doesn't work, you may need to disconnect the battery for half a minute so it will lose its memory of the old TPS.
When you have trouble getting the engine started in cold weather, two possibilities come to mind. First, turn the ignition switch on for a few seconds without cranking the engine, then turn it off for at least five seconds. Do that two more times, then crank the engine. Every time you turn the ignition switch on, the fuel pump will run for two seconds, then turn off. This is to insure fuel pressure is up for starting. If it starts normally now, suspect a leaking injector bleeding fuel pressure down while the engine is off.
Another thing to check is the coolant temperature sensor. As long as the voltage on it is between half and four and a half volts, it won't set a fault code, however, it still could be reading an incorrect temperature. If the actual temperature is colder than the sensor is telling the engine computer, the computer won't command a large enough priming squirt from the injectors. Usually this just results in long crank time or the need to hold the gas pedal down just a little to get the engine started.
Tuesday, April 28th, 2009 AT 12:48 AM