When the Car Won’t Start – No Spark, No Compression

There are few things as frustrating as getting into a car that won’t start.  Even more irritating is when your engine cranks and STILL will not start!  Before you hit an auto repair shop, let’s examine one issue you may be having. An educated auto owner is better equipped to understand and ask questions about what auto repairs their mechanic or auto repair shop technician advises. 

All engines require satisfactory fuel pressure, a precisely timed spark and regular compression.  If your vehicle’s engine cranks but doesn’t start, you are likely to be experiencing difficulty with one of these.

Engine Cranks – No Spark

Check the spark plug wires.  If they are cracked, wet, or burned it could be causing difficulty with the spark, creating a problem starting the car. Also check that the internal resistance does not exceed specifications, as this will cause the same problem.

You also need to examine the spark plugs.  When you remove the spark plugs, if they are wet they are either not firing or the engine is flooded.  If the plugs’ electrodes have been contaminated with deposits, this can allow the spark to ground before jumping the gap, causing the plugs to misfire.  This will make the vehicle hard to start and cause it to run poorly once started.

If there are cracks or carbon tracks on your rotor or inside the distributor cap, this can be causing problems.  Issues of this nature will allow your spark to short out to ground before ever reaching the spark plugs.

You may be dealing with a bad distributor pickup or faulty crankshaft position sensor. This is what sends the pulse signal to the ignition module or PCM.  Without this, there is no trigger for the ignition coils therefore, the car won’t start.

Another issue that you could have is a defective ignition module.  Since the ignition module is responsible for the firing of the ignition coils, a faulty one can create problems with starting and/or stalling. If you’re having a hard time starting the car, problems with sudden stalling, especially when the engine is hot, you may need to have the ignition module checked. 

Bad ignition coils can affect different autos in different ways.  Its purpose is to create a high voltage that fires your spark plugs.  On vehicles that have a distributor, a bad ignition coil prevents sparking at all of your spark plugs.  If you have a coil-on-plug or distributor-less ignition system, having a bad coil only affects one or two cylinders. While this can create some problems getting the car started, it will be able to run on the remaining cylinders once started.

Engine Cranks – No Compression

Take a look at the timing belt or chain.  A failure or breaking of the belt or chain keeps valves from opening.  Not only will the engine not run, you need to be sure that there are no other damages like bent valves that occurred due to the breakage.

When the engine starts but dies within a couple of minutes, you may have a plugged catalytic convertor.  When the catalytic convertor becomes obstructed, it creates restrictions that then cause your exhaust backpressure to accumulate.

If you have an overhead cam engine, check the camshaft.  If your engine overheats too badly it will warp the head, in turn seizing up the camshaft.  

As a Columbia, SC auto repair shop owner I want to inform drivers (and potential customers) about what their car troubles are and why they happen.  If you have car questions or need to schedule an auto repair or maintenance appointment in the greater Columbia, SC area, Sanford’s is happy to make you their newest loyal customer!