We’re going to pick up where we left off in part one where we highlighted some tips based on the scenario of the “won’t crank (or turn over), won’t start”. In this segment, we’re going to take a look at the other side of the coin – the “turns over, but won’t start” situation. If the engine cranks over normally when you attempt to start you car, but the engine does not start, the problem may be one of three things;
- No fuel
- No spark, or
- No compression
The engine needs adequate fuel pressure, a properly timed spark and normal compression to start. Some vehicle owners may have the tools, time, and knowledge to perform the following tasks on their own. If not, don’t go beating yourself up. If anything, you’ll be armed with more knowledge and you won’t feel like someone is speaking Greek when you talk to your mechanic
Tip #1 – To find out why the engine won’t start, remove the air inlet tube from the throttle body, push the throttle open and spray a small amount of starting fluid into the engine. Now turn the key. If the engine has spark and compression but no fuel, it will fire up and run a few seconds before dying. If the engine does not start, it probably has no spark.
Tip #2 – Another method to check for spark is to pull a spark plug wire off of a spark plug. This will only work if the engine has plug wires as coil-on-plug ignitions (or commonly referred to as coil packs) do not. Next, place the open end of the plug wire near a metal surface on the engine. Have a helper crank the engine while you watch for a spark. DO NOT hold the wire while doing this as it can shock you. If you see a spark, the problem is not spark, but most likely no fuel or no compression . If you do not see a spark, the problem is in the ignition circuit.
Tip #3 – We’ll be the first to admit this last pointer is on the technical side, but can be useful information none the less. Proper fuel pressure is critical for fuel injected engines to start and run. You should hear the fuel pump inside the fuel tank buzz for a couple of seconds when the ignition key is turned to start the vehicle. No buzz means the pump is not running properly and the engine is not getting enough fuel. You can also smell the tailpipe for gasoline vapors after cranking the engine. If you smell gas, the problem is likely not fuel but no spark. You can also remove the plastic cap and press the Schrader valve test fitting on the fuel rail to see if there is any fuel pressure to the engine (not a very accurate test because fuel pressure must be at a certain level for the engine to start, for that you need a gauge). Even so, no fuel at the fuel rail would tell you fuel is not getting to the engine.