I have a 1996 Ford Explorer and sometimes when I try to start it I have to crank it for about ten minutes until it will finally start. When it does finally start you have to push the gas to the floor and it will back fire a few times and spit and sputter then it will ram right up. The starter is turning over but just wont start. Also the door ajar light is staying on and all the doors are shut. The alarm is not working correctly and the dome lights will stay on. I am at a loss and don't know what in the world is going on. Any ideas?