Why does my Lexus have a rough start?
Any buildup on the throttle bore or butterfly valve will reduce airflow through the throttle (now sitting at it’s default position), causing the roughness or hard start. The higher the mileage the more severe the condition.
What’s the rough idle after a Toyota battery replacement?
Here’s a DIY from YouTube demonstrating his procedure for cleaning the throttle on a 2003, 2AZ powered Camry: As Eden Prairie and Chanhassen’s Toyota and Lexus repair specialist we hope this helps the DIY and professional auto mechanic alike sort out the typical rough idle after a Toyota or Lexus battery replacement, repair, or disconnect.
What happens when the battery is disconnected on a Toyota?
When the starting battery is disconnected on late model Toyota and Lexus vehicles the engine control module loses the learned position of the idle air control valve or throttle actuator motor (throttle-by-cable or throttle-by-wire, respectively).
Why does my Toyota Prius idle when the battery is disconnected?
We wrote about something similar on the Prius, being a common cause of the MIL. When the starting battery is disconnected on late model Toyota and Lexus vehicles the engine control module loses the learned position of the idle air control valve or throttle actuator motor (throttle-by-cable or throttle-by-wire, respectively).
What happens when you reset the ECU on a Lexus?
The ECU stores diagnostic trouble codes when it senses a malfunction so a mechanic can fix it later. It’s also the ECU’s job to store your driving data to customize your ride. For around the first 1,000 miles of the ECU being reset, the car adjusts to the driver’s typical driving style.
What causes a Toyota Prius to start rough?
A common concern DIY Toyota and Lexus owners call CARspec for is a rough idle, starting and dying, or a hard start just after replacing or disconnecting the 12 volt starting battery. We wrote about something similar on the Prius, being a common cause of the MIL.