on a 2007 accord it could be air in your cooling -heater antifreeze.check fo leaking hoses or loose clamps also fill rad and reserve to the top with anti freeze.hope this helps
do you have a/c switched on when this is happening a/c makes engine idle up and down as it cycles on and off
A car may idle up and down due to "Improper fuel mixture". (The fuel in the car may consist of an un-even balance of air or gas). However, there are a few other ways a car can idle up and down.
idle speed motor on the throttle body.
The most common cause of engine surging (rev up and down) is a dirty air filter.
A vacuum leak could cause that. The year, make and engine info would help us help you.
I believe its up, which ever one makes it idle faster
The engine will idle up and down usually. It can also idle high or real low. But other things factor in on how the idle air works
Your idle air sensor is bad.
there is an Allen screw and a nut on the throttle cable you loosen the nut and the screw and adjust it to make it idle up or down.
Because it also starts the air conditioning compressor which cycles on and off loading up the engine which changes the idle
air conditioning compressors put a load on the engine causing it to slow down, vehicles have an idle compensator which when the air conditioning is on speeds the engine back up to normal idle speed or" compensates" for the added load.
Cars often idle fast when you start them up. The automatic choke will make the car idles fast for a while then the idle speed will slow down, once the engine warms up.