When I place the key in the ignition and proceed to crank the car the key stays in the start position and the car is constantly trying to start itself up but never actually turns over. I then have to manually turn the key back so the car can stop trying to start up. I have had the fuel pump replaced and the crank position sensor. The car worked like normal for one entire day and then the same problem reoccurred. Though I don't think this is the problem but each time the car wouldn't start it was parked on a semi incline in our driveway. But we have parked it her numerous of times before. I am having a mechanic check the fuse boxes today for maybe a relay problem.
My car has 120000 miles.
My car has an automatic transmission.
First, let’s make sure about some terminology before I proceed. I will assume the motor is actually turning over. If the car is trying to start, the motor has to be turning over or it is not trying to start. This is an important distinction when diagnosing the starting system. As a technician, I go to different parts of the system based on this description.
If the key is stuck in the start position, this is a ignition lock cylinder issue and the reason the starter continues to turn the motor over. If the starter is turning but the motor is not, then the starter is likely the problem. Either that or the teeth on the flex plate are all gone. This would require removing the transmission to repair.
If the car runs intermittently, this can be a big challenge. And it also means the starting system is working. It will need to be diagnosed when it is failing. A working car cannot be diagnosed because there is nothing wrong. Where you park your car should not have any affect. It certainly could be a wiring problem. Wiring problems hide really well and can happen anywhere in the miles of wires that are in your car. Isolating the system that is failing is really important here. At the moment I am unsure which system is failing. Starter system, ignition lock cylinder and or ignition switch electrical or something with the engine control system.
When the car is failing, you need to check for spark and fuel pressure. If neither is present, this is a clue. Usually the crank sensor will do this. Does your car have a tachometer? If so, does it move at all when cranking. This is a clue whether or not the cam and or crank sensor is working. Is there a Check Engine Light on with the key on? If there is a Check Engine Light, the code or codes can be used for specific diagnosis.
All of these concerns will send you down a diagnostic path. Be sure not to confuse yourself by misinterpreting multiple system failures. If the key does stick in the start position, this would be the first problem to solve. After that, does the motor actually turn when the starter turns? After that, the question of "Why won’t it start?" is first answered by finding what the motor is lacking. Fuel, spark etc... Good luck.
If you need assistance with these checks, contact a certified mechanic who has the tools and experience needed to properly diagnose this starting issue with your car.