01 sentra no spark car wont start - 2001 Nissan Sentra

Thanks for choosing FixYa and welcome. If you have a vehicle that will turn over and over but will not start, I will tell you some things that you need to check. Every vehicle needs air, fuel, and fire to start. Now, the first thing you want to check is the fuel system. You want to make sure that the engine is getting fuel. The easiest way to test the fuel system is by testing the fuel pressure on the fuel rail. You need to refer to your owner manual for the correct measurement of pressure. Another easy test is using starter fluid. If it starts when you spray the fluid, you have a fuel issue. If it doesn't, check the ignition system. If your pressure is not correct or you have no way of testing the fuel pressure, start by checking your fuel pump. The fuel pump pumps fuel out of the gas tank and to your fuel filter. When you first turn your key on, you should be able to hear the fuel pump kick on for a second or two. It makes a soft buzzing sound. Listen for this sound. This will determine if the pump is kicking on and working. If you don't hear this sound, check your fuel pump fuse, relay, and your reset button. Not all vehicles have a reset button, so once again check to see if you have this button. If you change all of these and the pump still doesn't work, you may have a bad fuel pump. Test and make sure the pump is getting power before you change it. Now, you want to make sure the fuel filter is not stopped up. Check the gas lines and make sure they have no damage. Lastly, make sure fuel is getting to the fuel injectors. If you are getting fuel, you will need to make sure you are getting fire. You need to test your spark plugs or coils for spark. If you have spark, you should look over your timing belt or timing chain to make sure it is not broken or slipping. If you are not getting spark, you will need to check the spark plugs, coils, coil packs, wires, distributor, distributor cap, and rotor. Anyone of these can cause a vehicle to not spark. Check everything you can. Make sure the rotor is spinning and make sure the distributor cap has all metal contacts. Also, make sure the cap is not damaged or cracked. Make sure none of the plug/coil wires are damaged. Make sure they are all hooked up correctly. Now, it is possible that you could have a bad camshaft sensor or crankshaft sensor. In some vehicles, the camshaft sensor is built into the distributor. You want to test each of these parts and make sure each one is getting power. If a part is not getting power, that may be the reason your vehicle is not starting. If you have a check engine light on, you need to get your computer scanned for error codes. More then likely, if your vehicle won't start, your check engine light is on. The light is on because your computer has detected a problem with the vehicle. You can buy a cheap code reader for around forty dollars from Autozone or Advanced. Just make sure you know all your codes for your vehicle. When you have it scanned, the computer may know the exact parts you need to change. Most of these parts listed run off your ECM. The ignition system is a very complex system. It is rarely, but they do go bad. If you believe that the computer is to blame, make sure you have it flashed before you put it in your vehicle. If you don't, it will not work. Finding your error codes is the best way to finding your solution. If not, you will have many things to check. Always make sure you run a test on a part before changing it. Make sure that part is getting power. If it is not, check the power source. I know this is a lot of information, but any of the parts listed can cause the vehicle to not start. If you have no access to a code reader, fuel pressure tester, or a code reader, you can still check a lot of things. It is just harder. Remember, always use the process of elimination. Determine if the part is working or not and move on to the next part. You will eventually find your problem. Lastly, electrical problems can cause the symptoms you are having. They are very hard to find. When trying to find an electrical problem, you need to make sure you know what to test for. Each wire has a purpose. One part of the engine can shut down another part. You need to know how many volts you are testing for on each wire. You can use a voltage meter to test for current.