Chevrolet Repair: 00 Silverado 5.3 idle, mac mentor, fuel gauge

Question
I have an 00' 5.3 Silverado, 123k, good Fuel pressure, runs on all 8, drives well. Intermittent warm no start unless throttle is opened slightly (adding air), TPS is on the money @.72v. Cleaned Throttle blade and adjusted blade to 600 min idle warm, with IAC closed (Mac Mentor). Replaced IAC and checked connector good.

Fuel gauge sender is innaccurate and check engine light is inop.

Scans fine and has IAC control thru scanner.

Thanks, Kiwi  

Answer
I assume that since you have a scan tool and you said "scans fine" that there
are no codes ? you said good fuel pressure , did you hook up your fuel pressure
guage , check pressure and then let it set , see if it hold pressure. you could
have a fuel injector bleeding off .