Truck starting and idle problems!

Okay I got the 6g72 12v blah blah my truck has just recently started having an idle problem. I turned the idle screw up a full turn and got it to where it's not gonna fall on it's face. I replaced the timing belt about 8 months ago and the timing is dead on. When I start it in the morning idles perfect, throw it in reverse and it almost stalls. I checked the fuel filter it's clean fuel pump is an aftermarket one. I did a tune up last week. I'm stumped. I checked the vacuum lines and nothing is escaping. If I put this thing in 3rd gear at a 40 roll it will blast up to 85 mph. It's just the idle thing throwing me off. The compression ratio is different because i bored it out. It's a fresh build. I'm thinking about running it by a tune shop. Let me know sorry for the long post! Maybe it's the pcv valve! I'll check that next!! One more thing it starts right up cold no problem. But once it gets to running temperature it takes a minute to start.

I'd run an error code check first before throwing money at it. I'll take a wild guess at either a faulty ECU or a bad ignition coil, maybe an O2 sensor or the IAC solenoid is bad or clogged up... :shrug:

The check engine light comes on sometimes but it doesn't run any different.

The intermittent check engine light might mean a sensor is going in and out of it's normal operating parameters.