What causes high idle on start up?
The most common problem is a faulty fuse. In modern vehicles, engine idle speed is most often controlled by the idle air control (IAC) motor. This can be impacted by bad fuses in many different electronic systems in your car. Next, your high idling could be caused by a computer malfunction.
What should the engine RPM be before starting the car?
Your engine should normally get to around 700 RPM after you start the vehicle. If it is a few hundred RPM under or over that amount and you experience one or more of the problems listed above, then you will want to diagnose the issue right away.
What should the idle RPM be on a car?
Your engine should normally get to around 700 RPM after you start the vehicle, depending on the model. If your idle is way off and you have one or more of the problems listed above, then you will want to diagnose the issue right away.
How does ignition advance increase as RPM increases?
RE: ignition advance as RPM increases. The advance rate is not linear to rpm. The advance does not always increase with rpm, and at very high rpm, some engines respond to some top end retard. Some factors that change burn rate are, compression ratio, charge temperature, a:f ratio, fuel particle size and degree of vaporisation.
Why does my car rev up when I start the car?
Thank Kevin. Common causes of high RPM excursion at start-up are typically: large vacuum leak, throttle plate stuck open, cruise control stepper motor stuck in one position; faulty throttle position sensor, and/or faulty idle air control motor or solenoid.
Why does my car run at 1200 rpm?
Some cars, especially older cars with carburetors are designed to run at 1200 rpm or so until they are warmed up. And in modern cars, if you are running several accessories, such as the air conditioner or heater, the engine’s onboard computer may be telling it to run at a higher RPM to provide the necessary power.
Why does my car idle at a higher RPM than normal?
Updated January 19, 2019. If your car seems to be revved up to a higher-than-normal RPM while idling, it’s not necessarily a problem. If this problem happens while the engine is cold, it may be part of the engine’s design.
Thank Kevin. Common causes of high RPM excursion at start-up are typically: large vacuum leak, throttle plate stuck open, cruise control stepper motor stuck in one position; faulty throttle position sensor, and/or faulty idle air control motor or solenoid.
Why does a cam lobe miss at high RPM?
So a miss from a single, slightly flattened cam lobe will often start to go away as engine rpm rises and the lifter pumps up, but will probably reappear at very high rpm as the cylinder begins to once again starve for airflow. Engines with solid lifters may or may not experience low-rpm or idle problems.