OK, so I have my ideas about what this might be. Anxious to hear your thoughts.A few times now I have turned the key to start the truck and let go before the engine catches. So, I just twist the key for too short a time and the engine doesn't catch. Then I try again and it will crank and crank and now start for almost exactly an hour. Then it starts right up.There is an aftermarket alarm on the truck and I have no remote. Not sure if it ever had one. I cannot smell fuel in the tail pipe while cranking; so, no fuel is being delivered. When it does start, I will fire right up with just a small puff of black smoke at the tailpipe. So I don't think there is a ton of fuel flowing.Do alarms shut off the fuel on a diesel?bb