I have a 1996 Chevy Silverado K1500 6.5 turbo diesel auto,the throttle pedal has twice now not responded when pushed,the only thing to do is to switch off the engine and restart after which it works fine,but when restarted the transmission seems reluctant to change up above 2nd gear ? After stopping the engine and leaving it off for short period of time the transmission also works fine again ?? Anybody had this problem before ?