First get the slack back in the throttle cable. When the engine rocks, that cable has to be able to flex. If there is no slack in it, the cable can be tugged on, affecting idle speed.
Idle speed is controlled by the Engine Computer. The adjustment screw, which is not used by most manufacturers, sets the very low idle speed needed to prevent dieseling when stopping the engine, so put that back too. If you recently disconnected the battery or let it run dead, the Engine Computer might need to relearn "minimum throttle" before it will know when it must be in control of idle speed. I have not heard of that before with Hondas, but it is real common on some other car brands. There are specific sets of conditions it takes to cause the relearn to take place. The only one I have memorized is for Chrysler products. That involves driving at highway speed with the engine warmed up, then you must coast for at least seven seconds without touching the pedals.
If you need to do something similar, the symptoms typically are you might need to hold the accelerator pedal down 1/4" to get the engine to start, you won't get the nice idle flare-up to 1500 rpm's at start-up, and it will tend to stall at stop signs.
Also check for vacuum leaks. The automatic idle speed, (AIS) motor is a computer-controlled vacuum leak. Idle speed will vary if that leak is trying to overcome or work with another unknown leak. Related to that, check the fresh air tube between the mass air flow sensor and the throttle body. There must be no loose hose clamps, cracks, or other leaks. If any air sneaks into the engine that does not go through the mass air flow sensor, it wont be measured, and no fuel will be calculated to go with it. That can cause erratic idle from an excessively lean condition.
Friday, December 2nd, 2016 AT 7:18 PM