Why does a turbo spin up when the engine is under vacuum?
@generalexception, you just answered your own question: if the engine is under vacuum, it has little load. The throttle must be nearly closed, reducing the total air mass through the system. As the throttle opens, the turbo will spin up as the exhaust energy increases.
Why does a turbocharger only produce boost when the engine is running?
For example, when rolling down hill, you don’t need to hit the throttle so the entire intake to exhaust path is pumping a smaller air mass. However, driving uphill will require you to open the throttle (give it gas), adding air to the intake.
What causes a car to run lean on a hill?
If the fuel filter is not changed for a long time, eventually the particles and sediment from the gas tank will build up and clog the filter, restricting fuel flow. If the flow of fuel is restricted too much, not enough will be able to reach the fuel injectors and the car is likely to run lean.
Why does my car run flat on its face when going up a hill?
A symptom of starving the car for fuel is a car that runs correctly at idle and low load, but falls flat on its face as you ask for more power (when climbing a hill, for instance). Fuel pumps may fail due to age, sediment buildup, or running the incorrect fuel.
@generalexception, you just answered your own question: if the engine is under vacuum, it has little load. The throttle must be nearly closed, reducing the total air mass through the system. As the throttle opens, the turbo will spin up as the exhaust energy increases.
For example, when rolling down hill, you don’t need to hit the throttle so the entire intake to exhaust path is pumping a smaller air mass. However, driving uphill will require you to open the throttle (give it gas), adding air to the intake.
When do you not need to hit the throttle?
If we’re talking about an engine that is operating “under load”, we can assume that you’ve opened the throttle. For example, when rolling down hill, you don’t need to hit the throttle so the entire intake to exhaust path is pumping a smaller air mass.
How does a turbo work on a diesel engine?
See, on a engine with no load, even without a wastegate the turbo is not doing much. and to make things a bit more complicated here, on a diesel engine it works similar but different. There is no intake air regulation on a diesel, the intake is always unrestricted and output is determined by the amount of fuel injected.