High Idle and check engine light glowing

I have had a major tune-up today ( wires, plugs, rotor, ignition cap), replaced the map sensor, 3 diverter valves, scoped also.

Check engine light is still on and the idle is high in drive and at stoplight. Coolant temp sensor might be culprit of check engine light.

What should the idle be in drive and at stoplight? I know that it is preset.

Can’t answer unless you describe the vehicle.

First things first. Year, make, and model of vehicle. Engine too if there were optional engines.

And now…start with the codes, don’t start with the idle. I’ll bet my mmorning muffins that if you fix the cause of the codes you’ll fix the idle.

So, what are the codes?

Do you have a Saturn? Are you getting a code P0507? If yes, then you need a new intake manifold gasket. With the engine idling, spray some WD 40 around the #1 cylinder and see if the idle doesn’t momentarily slow down and smooth out.

The car is a 1982 Corvette. I do not know what the codes are. I will find out from my mechanic.
The engine is a 350 V-8, the only one offered.

The car is a 1982 Corvette with a 350V-8. This was the only engine for the year and came with an
automatic transmission.

The car is an 1982 Corvette with the standard V-8. The car has 36,000 original miles on it.