120,000 miles.
1. Runs rough at idle. Rough enough to shake the steering wheel. It has done this for at least 30,000 miles.
2. When the engine is warm it starts immediately. After it has set for awhile or overnight the engine will crank a long time, 30-45 seconds, before it starts. The cranking time seems to be increasing.
3. How often should the timing belt be changed?
I replaced the sparkplugs and air cleaner about 10,000 miles ago. Replaced the fuel filter about 2,000 miles ago.
I am willing to do what it takes to make this engine run well. I would like to drive this Honda for another 100,000 miles.
Thank you in advance.

. Replace the Ignition Control Module (ICM) and coil:

https://www.askmehelpdesk.com/cars-t...tml#post265896

I recommend replacing these problematic components every 120,000 miles or 10 years, whichever comes first.

. Clean the Idle Air Control Valve (IACV):

https://www.askmehelpdesk.com/cars-t...ml#post1054149

. Replace the Engine Coolant Temperature (ECT) Sensor, if the problem persists. This sensor affects fuel injector pulse width. The ECT Sensor is a temperature dependent resistor (thermistor), whose resistance decreases as the engine coolant temperature increases. It provides a richer mixture when cold, leaner mixture when hot. They become corroded, due to not changing the coolant frequently enough. This sensor has a 2-wire connector, while the ECT Gauge has 1-wire.

. Replace the timing belt every 90,000 miles or 7 years, whichever comes first.