If an engine is not getting enough fuel (this is called “running lean”), due to fuel pressure (regulated by the fuel pump and regulator),
restricted fuel injectors
, a vacuum leak or really anything that throws off the fuel mixture going in to the engine, this can cause the surge.
Can a dirty throttle body cause idle surge?
A clogged or obstructed air filter can cause surging at idle
, and foreign objects can enter the filter housing at any time. … Clean the throttle body or carburetor venturi(s) after replacing a severely dirty air filter. Aerosol products designed for this purpose are available at any auto parts store.
How do you fix a surging idle?
Turn the engine off again, and reattach the air intake duct work to the throttle body. Start the engine and rev and hold to 1,500 to 2,000 rpm until no white smoke is coming out of the exhaust pipe. Cleaning the
Idle Air Speed Control Valve with aerosol throttle cleaner
can often solve an idle problem.
Why is my car idle going up and down?
If
the engine can’t keep idling, it will keep trying to get the engine revved up to compensate
. The cause of the erratic engine you’re experiencing could be a vacuum leak, sensor failure, or an EGR system malfunction.
What causes fluctuating rpm at idle?
Why does my engine’s RPM seem to fluctuate (runs rough)?
Many engine performance problems can be linked to maintenance issues such as stale fuel, dirty air filter, fouled spark plug, and deteriorated oil. … Engine hunting and surging at idle is usually caused by
a fuel delivery, air leak, or governor system problem
.
What are the symptoms of a bad idle control sensor?
Common signs include
irregular or unusually high idle speed, the Check Engine Light coming on, and stalling while idling
.
Can bad spark plugs cause engine surging?
3. Surging and Lagging. Another good indication that your spark plugs are dirty or worn is if your
vehicle experiences surges of speed
, resulting in a jerking acceleration. These surges occur because your spark plugs are not igniting the fuel in your engine at the proper rate, resulting in an uneven speed.
Why do supercharged engines surge at idle?
What makes the blower “surge”? This is caused
by a rich/lean cycle at idle
. As the motor leans out, the RPM’s increase and richen up the motor, when the motor richens the RPM’s decrease and the motor leans out again. This continual cycle is known as “blower surge”.
What does engine surging feel like?
You can even experience a bit of a delay when trying to accelerate. Moreover, it’s common for you to hear some noises coming from your engine during car surges. These noises usually
sound like popping and backfiring
. In some instances, your car’s engine might simply sound different than usual.
Can a faulty oxygen sensor cause engine surging?
Oxygen sensors are among the most interesting and important sensors on your engine. … Surging is among the many problems a failing O2
sensor can cause
, but it isn’t the only one.
Can a dirty air filter cause high idle?
A
clogged filter will reduce the flow of air into the engine
, causing a rough idle. It may also increase your fuel consumption. Replacing your air filter is a simple process of removing the old one and replacing it with a new filter.
What should my rpms be at idle?
For regular cars, idle speed is typically
between 600 and 1,000 rpm
, just enough to keep the engine’s ancillary systems going, but not enough to move the car forward much.
What are the signs of a bad fuel pump?
- Sputtering Engine. Your fuel pump is telling you something if your engine starts to sputter once you’ve hit the top speed on the highway. …
- Overheating Engine. …
- Low Fuel Pressure. …
- Power Loss. …
- Surging Engine. …
- Gas Mileage Decrease. …
- Dead Engine.
What is considered excessive idling?
Excess idling is defined as
maintaining a stopped vehicle with the engine running for five (5) minutes or longer
. … Idling for more than just 10 seconds uses more fuel than restarting the engine.
What causes rough idle when warm?
A Wonky fuel pressure regulator
can cause rough idle when warm. … Once warm, a bad fuel pressure regulator can cause a rough idle by leaning out the mixture due to low fuel pressure.
How do I reset my idle air control valve?
If you removed the air intake, ensure you reconnect the MAF sensor (if equipped).
Turn the ignition ON and leave on for several seconds then turn the ignition OFF to allow the ECM
to reset the IAC valve. You should be good to go.
