Hi!
Lately, when first started, the (cold 30-40F outside air) engine idles very roughly.
It will also miss fire occasionally. Just about the time when the thermostat opens,
the idle goes to 3500-3750 rpm by itself and will not come down for about 90 seconds
(until the engine is further warmed up). However, once the engine *fully* reaches
operating temperature, it runs and idles normally. If I turn off the engine before
it's fully warmed up, it will diesel (sputter-sputter) for 5-6 seconds before
stopping. It will crank but not start for 10-20 minutes if I try to immediately
restart it.

It's a mystery to me why it runs normally when at temperature, but has all these
problems when cold and is started.
Any suggestions appreciated.
Ken