i have a 2004 mercury mountaineer that will turn over but not start. i have replaced the fuel pump and it still will not start
Then the fuel pump wasn’t the problem. Why did you replace it? Wasn’t it running? Did you check the relay? Did you check the fuel pressure?
Car’s need fuel, air and spark to run. Make sure it is getting all 3. If you want any more help, please post the mileage, engine type and whether or not the check engine light was on before this started.