Really need help I'm just shade tree mechanic truck was running okay except lack of power and pressure gauge dropped at idle. Decided to change the oil cooler and do an egr delete while i was there i replaced orings on hpop and replaced all orings on the injectors cleaned brass shavings out of ipr and dug out and extra screen that was lodged in there. While i was there i tried perform air test but didnt have pigtail for ipr , so couldnt be sure . After that i cleaned turbo and put it back together . When went fire it up wouldnt.start at all . One thing i forgot was to purge air by turning key back forth three times until i cranked once . Very frustrated at this truck now . How can oil cooler change and installing new orings result in a no start.