2005 Silverado 2500 6.0 w/ automatic trans. So prior to the following work all was fine. Don't remember if this started immediately after the work or a few days later. I dropped the trans to fix a rear main oil leak. At the same time I replaced the oil sender, cam position sensor then I lightly pressure washed the undercarriage. No cleaning top of motor. No other work was done. The truck will start first turn of key about 30% of the time others I turn the key it cranks but doesn't start release key and starts right up second try. When it starts, it runs smooth. Ive tried the turn the key on, off several times to prime the pump didn't help. My initial OBD check was showing P200 and P0300 codes, I erased them and tried to reproduce by driving and it will not produce any engine codes. It can set for 5 mins or overnight, hot or cold the problem can happen anytime. I have checked fuel pressure jumps right up to 54lbs each time does bleed off to about 40 after an hour. Checked power to the injectors both when it starts and when it only cranks, getting power. I don't like to give up but im at a dead end on what to do. Appreciate any input. Thanks in advance