> Hope someone can help me with 2 problems. ('87 5Kcst, not a q). My
> coolant temp gauge reads intermittently. ...
This is a common problem. The sender is usually at fault since it has
a hybrid circuit in it and the temperature changes over time cause the
solder to crack. Your symptoms fit the list exactly. The sender is pricey,
about $80 last time I had to buy one, but supposedly the design has changed
and what you buy now sould never need to be replaced again.
> Second problem concerns the ignition warning light. ...
Just a guess here. Wonder if your knock sensor is kaput.