1997 k1500 5.7 I have no injector pulse. No start. New timing chain, crank position sensor, cam position sensor, knock sensor, 3 wire oil pressure switch. Checked reference, ground and signal continuity to each sensor. Checked spark at the plugs and compression, both good. 60 psi @ the fuel rail during crank and prime. Have a scanner hooked up and reads 0 pulse width. Also checked power at injector plug and all fuses. I am stumped! Can anyone give me a hand?