1991 Mitsubishi 3000gt sl It won't turn over, any ideas?

Explosions are not good but they rarely blow a motor unless you have a crankcase full of nitro. It might has been a backfire through the intake. Charge the battery, remove the plugs, squirt a little oil in each cylinder and try the starter. If there are no clanking noises, put the plugs back in.

U mean that I have to remove d intake manifold again ?

Sounds like damage done so you probably can't hurt it any more. If it is a manual transmission u could try to pull start it with another vehicle.

What kind of damage ? It's an automatic transmission

Maybe the explosion was a back fire causing the engine to go backwards while the starter was engaged thus creamed the starter.

I think the timing belt get loose :/ too, so do I have to remove d starter and test it then?

I would see if you can roll engine over either forward or backwards by putting a socket and ratchet/breaker bar on main pulley bolt. If your strong and can get two hands on the pulley that might work as well. If you can move it at all, least you'll know it's not locked up. Try that

If timing belt is loose or jumped time do not turn motor over until you get it sit and tight. That is an interference engine and you will take out at least six of the valves. If you think it is an issue take the time to break it down and check the belt. If you have already turned it over do a compression check. You should have somewhere between 150 and 200 psi on each cylinder if all are not at least within 5 psi of each other I would look deeper into what's going on with them. Any showing 0 psi will probably be due to bent valves.

You have to get the engine to budge even a little to see if it is seized or not.

If timing belt has jumped time and will not turn over with starter and you have to use a pull bar to turn it over you just bend at least six valves. If starter will still turn it over then the valves are clearing the pistons or are already bent. And according to how hard you pull on the pull handle you might also be buying new pistons. These cars are known for bent valves due to loose or other timing issues. Starter does not have enough power to bend the valves if they are hitting the pistons. It will seem locked up.

If you think it is locked up remove the timing belt. The springs will push the cams to a neutral position( all valves closed). You will see the cam pulley spin to this position but use caution not to have your hands near the cam pulleys when this happens. And then you can try and turn it with a pull handle.

Actually it stared again just to find out that it have a bad ECU bc injectors don't stop spraying fuel, thanx everybody for your help, you guys been very helpful :)

Ok and good luck with it. They are fun cars.