Can a car refuse to open the throttle?
Engines with throttle-by-wire (also known as an electronic throttle) may not allow you to open the throttle during cranking. These engines can refuse to start while the throttle is not at the idle position.
What’s the difference between open throttle and closed throttle cranking?
It is impossible to come up with a hard number for how close the closed-throttle cranking pressure will be to the wide-open-throttle (WOT) cranking pressure because of the differences in idle bypasses, cranking speeds, and idle speeds between engines.
Why do you have to open the throttle during compression test?
Almost every compression testing guide tells you to hold the engine’s throttle wide open during a compression test, but most won’t tell you why it may (or may not) matter. On gasoline engines, the throttle is a valve, which reduces the amount of air going into the cylinder.
Why does my car not start when I crank the engine?
If there’s a spark when the engine is cranked, it has ignition. The problem is either fuel or compression. This gives time for the fuel pump to pump fuel from the tank in the back to the engine in the front.
Engines with throttle-by-wire (also known as an electronic throttle) may not allow you to open the throttle during cranking. These engines can refuse to start while the throttle is not at the idle position.
Almost every compression testing guide tells you to hold the engine’s throttle wide open during a compression test, but most won’t tell you why it may (or may not) matter. On gasoline engines, the throttle is a valve, which reduces the amount of air going into the cylinder.
It is impossible to come up with a hard number for how close the closed-throttle cranking pressure will be to the wide-open-throttle (WOT) cranking pressure because of the differences in idle bypasses, cranking speeds, and idle speeds between engines.
What causes a car engine to start cranking?
Normal service items: Prolonged cranking can be caused by a dirty throttle bore which can disrupt the airflow into the engine. The throttle actuator (throttle bore on older vehicle – cable) is an electronic throttle control which will get a condition called “coking” which is a kind of light tar like goo on the butterfly and its inner body.