How To Troubleshoot A Car That Won’t Start?

It’s infuriating when your car refuses to start, and you curse yourself as who buys used cars near me. You crank the ignition key, but nothing occurs. Almost every vehicle owner has encountered this. Numerous things may go wrong with your vehicle, but there is usually always a solution. Often, the cause is as simple as a dead battery.

Once you understand which stage failed, you’ll have a clearer understanding of why your vehicle won’t start or what to do. You may contact your local mechanic, but if you’re interested in troubleshooting why your vehicle won’t start, this blog is for you.

Perform a memory check on the problem code memory.

Most vehicles manufactured after 1998 contain an OBD2 system, which makes reading problem codes very simple. Whether the engine cranks but will not run, use an OBD2 scanner to see if any problem codes are recorded in the trouble code memory. In many cases, understanding the problem codes allows you to skip past stages and go right to the component that needs fixing.

OBD2 codes provide information regarding the problem codes. If you own an older American car, there is a possibility that you have OBD1 codes that can be read without the use of a scanner.

Conduct a visual inspection of the crankshaft/camshaft sensors

The next phase is to verify the crankshaft and camshaft sensors’ RPM signals. This is accomplished by visually inspecting the tachometer for RPM readings on the panel. It is better to use an OBD2 scanner to determine the value of the crankshaft revolutions per minute from the engine control unit.

Most instances, if there is an issue with the camshaft or crankshaft sensor, a fault code will be generated.

And in advanced troubleshooting, you can also use an oscilloscope to evaluate the signals from the camshaft and crankshaft sensors to determine whether they look normal or not. In most cases, you can only make corrections if the engine control unit registers any RPMs and there are no stored trouble codes.

Inspect the injectors for proper operation

Another reason is that the injectors do not open properly and do not feed gasoline into the engine. Typically, a blown fuse/power wire is the culprit, but in rare instances, it can also be caused by a faulty engine control unit.

To determine if the injectors are opening, use a multimeter to measure the voltage. Typically, injectors have two pins, one for 12+ power and the ground to the engine control unit. Assure that one of the wires has 12V while cranking, and use an LED light to check for any ground signal. Advanced injector troubleshooting should be performed with an oscilloscope.

The fuel injectors frequently make a tiny clicking sound as they open, which you may hear if you pay attention. Let someone crank the engine and see if the injectors click. When they are clicking, the injectors should be fine. Additionally, inspect the spark plugs – if the vehicle is pumping gasoline, they will be moist but not generate sparks.

Verify that the fuel pressure is correct

If the camshaft and crankshaft sensors are in good condition, it’s time to check for fuel pressure. A clogged fuel filter, faulty fuel pump, or faulty fuel pressure regulator may contribute to low fuel pressure. This results in your vehicle failing to start. Low fuel pressure is a common reason for your vehicle not to start.

You may use a fuel pressure gauge or an OBD2 scanner to check the fuel pressure if your vehicle is built with a fuel pressure sensor. If it has a fuel pressure sensor, you will certainly receive a trouble code indicating that the fuel pressure is too low. However, it is always prudent to verify the reading with a stick shift fuel pressure gauge.

It’s possible that the fuel pressure pump isn’t pumping any fuel, in which case you should examine the wiring, the relay, or the fuse. If it does not start but receives electricity, it replaces the fuel pump. If the gasoline pump is operating normally, replace the filter and troubleshoot the fuel pressure regulator.

Inspect The Ignition Coil’s Spark Plug

Another frequent cause of a vehicle not starting is a lack of spark. This may be due to a faulty spark plug, ignition cable, or ignition coil. The wirings could also indicate a problem with the ignition coil or a lack of transmitter from the crankshaft sensor, so always start with the crankshaft sensor.

Remove the cable/coil and spark plug to verify the spark. Connect a cable between the plug and a good ground point and allow someone to crank the engine while you check for spark. Remember to keep your hands away from the spark to avoid receiving a severe shock.

Conduct a compression/leakage test

To finish troubleshooting a vehicle that won’t start despite having gasoline and ignition, you should look at compression and leakage through the piston rings. To begin, you should do a compression test using a compression tester to ensure that all cylinders have the same pressure. Consult the maintenance manual to determine the proper pressure for the engine. While worn engines may have somewhat reduced pressure, the pressure between the cylinders should be consistent.

A leak-down test is designed to determine whether any pressure is passing through the piston rings to the engine’s bottom. This is an effective technique for identifying fractured pistons and piston rings.

Conduct a Crankshaft/Camshaft Timing Check

A worn-out timing belt or a timing chain may cause severe engine damage and cause your vehicle to refuse to start. Almost all engines feature TDC markings indicating the correct alignment of the camshaft and crankshaft. You must locate these markings either in your vehicle’s service manual or online. Then you must verify that the time is accurate.

A jumped timing belt or timing chain will result in broken valves in nearly all cars. If you think that your chain or belt has slipped, always do a compression test to ensure enough compression and that the cylinders are not bent.

Check the Alternator

If the vehicle starts but then stops, or if the interior lights begin bright and then fade, the alternator may be to blame. Additionally, the battery sign may show on the dashboard, and you may detect a burning smell, as the alternator is belt-driven. There is no quick cure, which is why you should see an expert. If it is defective, it may have also harmed the battery.

Locked Wheel

If the steering wheel of your automobile becomes caught in the locked position, the vehicle may be unable to start. Avoid yanking the wheel too forcefully. Rather, utilize a side-to-side motion with the key inserted or use a duplicate key if possible. Your existing one may be worn down and incapable of communicating with the lock tumblers.