Why does idle motor it self have so much delay?
The idle motor it self has quite a bit of delay to get the mass of the motor internals moving. The engine itself has the most delay from air fuel volume changes to resulting RPM changes. So say your engine is at 600 RPM and the idle controller makes a change to the ISM to increase the RPM.
What makes the engine ” hunt ” or ” oscillate “?
Any adjustment arrives way too late to correct the mixture in real time so it is always “running behind”. Makes the engine “hunt” or oscillate because the mixture is always changing which affects the idle speed so the idle motor is always trying to correct the speed. That just impresses another harmonic over the Lambda’s oscillations.
Why does the idle controller increase the ISM?
The engine itself has the most delay from air fuel volume changes to resulting RPM changes. So say your engine is at 600 RPM and the idle controller makes a change to the ISM to increase the RPM. If it does not wait for all those delays and makes another RPM reading then it will still see a low RPM and keep increasing the ISM to compensate.
How does the idle controller calculate the RPM?
RPM is computed by the time between one (in our case they use two) ignition pulses. The idle controller reads the RPM and moves the idle motor to compensate for a deviated idle RPM. The idle motor it self has quite a bit of delay to get the mass of the motor internals moving.
The idle motor it self has quite a bit of delay to get the mass of the motor internals moving. The engine itself has the most delay from air fuel volume changes to resulting RPM changes. So say your engine is at 600 RPM and the idle controller makes a change to the ISM to increase the RPM.
The engine itself has the most delay from air fuel volume changes to resulting RPM changes. So say your engine is at 600 RPM and the idle controller makes a change to the ISM to increase the RPM. If it does not wait for all those delays and makes another RPM reading then it will still see a low RPM and keep increasing the ISM to compensate.
What causes an idle motor to exaggerate the hunting?
Vacuum leaks are a big cause of exaggerating the hunting. The idle motor doesn’t have enough power to overcome a lot of “False Air” or air leaking into the induction system after the air sensor plate. A big and common source of leakage is old injector seals.
RPM is computed by the time between one (in our case they use two) ignition pulses. The idle controller reads the RPM and moves the idle motor to compensate for a deviated idle RPM. The idle motor it self has quite a bit of delay to get the mass of the motor internals moving.
Vacuum leaks are a big cause of exaggerating the hunting. The idle motor doesn’t have enough power to overcome a lot of “False Air” or air leaking into the induction system after the air sensor plate. A big and common source of leakage is old injector seals.
What to do when your idle speed is too high?
Try disconnecting the vacuum hoses to the AC and PS actuators and see if the idle speed drops slightly, then reconnect them and turn on the AC and turn the steering to see if the actuators do anything. As has been said above I also can’t see a link between a battery change and the fault.
How does the idle speed of a car work?
This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed.