I have a 2004 Chevy Express 3500 van with a 6.0 engine, has only 35,000 miles on it, but has been sitting for about 8 years. I replaced the fuel pump, because the only way was running if I put some gasoline into the intake manifold. So far I put a new ECM, new crankshaft sensor, a new oil pressure sensor, replaced the complete fuse box with new fuses. My Snap-on scanner tells me that I have to have the crankshaft sensor relearn procedure done, but the vehicle will not start, so how can I do the relearn procedure without the engine running or even starting. Your input is greatly appreciated. Thank you.
the engine should still start without the relearn.
You are probably still facing fuel delivery problems. Possibly bad injectors.
Start by measuring fuel pressure and testing for leakdown. Your snapon tool should also have a fuel injector balance test.
Was the new ECM programmed properly? If the anti-theft system is armed it will prevent fuel delivery.
Thank you. I will check on a few more things.