Car cranks but don’t turn over

When you first turn the key to start, the computer energizes the fuel pump to rebuild pressure loss, examines the engine coolant temp and ambient air temp to determine what air/fuel mixture should be. Since it starts when you depress the pedal, the first thing I'd check is the engine coolant temp sensor to see if it's telling the truth. When you depress pedal during a start, you're over-riding the computer and telling it to provide more gas, so the computer is obviously not giving it enough. Temp sensor might be off just enough to make this problem

Have you removed or changed your battery lately? If that's the case, the ECU resets. This is normal, it needs relearning. Will return to normal. or try to clean also the throttle body. ;)