Engine spins but won’t crank

Cranking is starter action, so it cranks good but won't start? Make sure battery has a full charge and connections all good. Have a helper crank it while you visually check for spark at the plugs. If spark everywhere, use a gage and check proper fuel pressure. Check fuel injector pulse? Any applicable trouble codes? Those are the basic checks, in my opinion. Let us know?

Think he is saying the starter is working fine, it's turning the flywheel (engaging and disengaging as it should) so starter, starter solenoid, and starting circuit are working, but no spark. I want to ask OP can you see if flywheel is indeed turning, is crank pulley spinning as well? Are you making compression? If yes, and crank is turning, and no spark then check crank sensor. Check for spark, check for injector pulse. Check cam, knock sensors. If those are missing you may want to pull cam sensor assembly/shaft, check gear isn't slipping on cam. Maybe i'm reading to much into the question but your description makes it seem like something in the bottom end isn't spinning when the starter is engaged.

The crank pulley is turning when I try to start it. It’s turning everything the serpentine belt is connected to also.

I haven’t had time to go real deep into the issue with my truck just yet but did notice that the computer cable was loose so I cleaned and reconnected it. I tried starting it while pumping the gas and it back fired through the intake. Not a loud bang but just kind of a putt. Also the lightning bolt symbol is on on the dashboard. Could it be an issue with the throttle control module? )⚡️(

Did you figure your problem out? I just had the same problem today with my 2011 Ram. I was driving on the highway and the engine shut off. Now it's doing exactly what you described.

I did figure it out and finally got it fixed. I didn’t mention but it over heated earlier in the morning that it shut off. Long story short my mechanic pulled one of the spark plugs out and put a camera down in the hole and apparently one of the valve seats had come out so no compression. Found same issue on other side of the motor. Pulled the heads off and found every valve seat in the heads had come out. The machine shop I used said they had only seen that happen once before but had heard it could happen. Tools for machining the original heads can get worn( or brand new sharp) and over size the hole just a little over tolerance and once it gets hot they can pop right out. The valve seats didn’t hurt my pistons but I did have to have the heads machined and new valve seats installed. Good luck

Thank you for the response. I'll let you know if I have the same problem.