Starts and runs well. No evident loss of power. Stumbles at idle. 5 speed manual

Thanks for the reply!! Ignition components (plugs and wires) are fairly new (less than 5K miles) and coil tested to spec. No distributor on this car. Compression checked out ... all w/i 5% of each other. Any other ideas?

try testing the plug wires just in case, also check for cracked spark plugs, ignition module, throttle body maybe pluged and spark plug gap

Reasonably sure that the problem is not with ignition or fuel delivery systems. Any idea what mechanical issue(s) might cause this problem?