Hello. I have a problem that I can't track down. When the car is cold it runs like a bat out of hell. After about 5-8 minutes of driving my throttle blade closes completely and recovers immediately over and over making it impossible to rev up. If I drive it long enough the throttle stops responding completely and if I let it sit, engine off, after a couple minutes throttle resonse returns but still cuts out. Another weird thing is when turning right the throttle stops responding( once again intermitently). I have switched multiple parts from another vette without luck; TPS, THROTTLE BODY, WATER TEMP SENSOR, CRANK SENSOR, TAC MODULE, PEDAL ASSEMBLY, PCM. I have also checked and cleaned all grounds, even added extra ground wires. I don't see any problems in the harness and the tune is the same as when it was running strong. No DTC present( no limp mode). Map and Iac are reading as they should. This problem came out of nowhere, car was running perfect since build.

A little history on the car: 5.7 ls1 forged dss pistons, eagle rods, prc heads, custom grind cam, holley hi ram, 242lb fast injectors, twin DW fuel pumps( 2 supply lines, 1 return, fuel psi 58 on a 1:1 ratio), twin 70mm turbos at 15psi boost.

Thank you for reading and your help is greatly appreciated!
-Chris