1990 CRX Si, 181,000mi
A few times a year I have had a problem starting the car. Car would
start up when the key is turned but die as soon as the key is let go.
Had the problem this week, got it started but then 15 miles later when
I stopped at a light I saw wisps of white smoke coming from the
steering column (never good!).

Turned out to be the ignition starter switch. It was wearing out (dirty
& worn inside). One of the contacts was arcing and heating up, enough
to melt the solder on one of the leads!

This switch sits behind the ignition lock and is attached with 3 screws
(you get to keep the same keys).

Instead of just cleaning it, I bought a replacement switch from Auto
Zone. Got a Wells part #LS883 for $60. Direct replacement except one of
the screw holes was too small for the existing screw - replaced screw.

Now, the car starts right up and even appears to idle much more
smoothly.

Hope this helps someone else in the future...

A