have a 01 lb7 no codes will crank over sounds fine no getting smoke out tailpipe swapped ficm with good out of another running truck. have plenty of rail psi will build up to 10,000. have ignition voltage and grounds on both connectors on ficm verified rpm signal. ohmed out the control wires. everything on scan tool reads fine. ohmed out injectors all around 0.3 0.4. at ficm harness connections also load tested and ohmed out the communication wires all good there too. truck has sat for 8 months before i got it was hit the ps door. ive also tried bypassin the fuel filter head used a clear hose to 5 gallons of fresh diesel. can see the fuel ppull up into the injection pump. only thing im not sure on is the supply voltage to injectors out of ficm i have .5 volt koeo and cranking it bounces from 4 to 11 volt just all over the place. and i havent been able to find the actual reading for the ground controls to injectors either. im tempted to swap ficms back and verify the swappped one is still good. no codes. i can un plug a harness for injector and it will pull a code for the open circuit. trying to verify communication between modules