blitz440

Hi my name is Gary I have a 95 k1500 Chyanne 5.7 I bought last week with 130.000 mi. It is extremely sluggish so i plugged a scanner into the obd port and it would not communicate so I checked the cig lighter fuse it wag good so i decided to go commando and spend some money! So far Iv replaced... dist,ecm,icm,map,o2,fuel filter,fuel pump,plugs and a tbi service kit. Compression is good! I have also checked the entire engine for vacuum leaks and there are none although better the truck still runs hesitant and sluggish also my gauges are kind of funny when I turn the ignition off the tach stays at last idle position until I turn ign back on I would greatly appreciate your help and advice. Thank You,
Gary Lollar