Engine turning over but not starting what is the problem?

There are only three possibilities or any combination thereof:

It's either fuel, ignition or compression.

I know that doesn't give much information, and unfortunately, that's the best that anyone can do without seeing the vehicle or knowing more about the problems.

Fuel delivery is a quick and easy thing to diagnose. Purchase a can of starting fluid and spray it into the throttle body as an assistant attempts to start the engine. If the engine starts briefly, you have a fuel problem. The starting fluid has replaced the normal fuel and if the engine runs with starting fluid, everything else just checked out ok. At that point, check the fuel pressure at the pressure test port. You may need to buy, rent or borrow a fuel pressure gauge and while you're at it, see if you can figure out how much pressure you're supposed to have. Just slowly isolate the problem, one piece at a time and you'll get there.

If the starting fluid didn't help, check for spark. Sometimes an ECM can go bad and you won't get any spark. If that's the case, you'll get a computer diagnostic code. In this case, buy, rent or borrow a code scanner for your vehicle and determine what if any codes are showing. The computer will tell you if it thinks anything electronic is wrong.

Unfortunately, the computer doesn't usually tell us much about the fuel pump or fuel pressure, so good luck with that.

you need to check your crank sensor it will not let spark to your plugs if it is not reading crank motion. It is located in front of the oil pan under the engine; cost about a hundred bucks and very easy to change