Skip the auto shop - Our mechanics make house calls

Q: Car turns over but won't start.

asked by on

My engine fails to start. It turns over, and I hear scattered, weak pops. There's some kind of combustion happening, but it won't crank. When I pulled the plugs, I got a spark, but it was very weak. The plugs themselves didn't look good; they were fouled up and the electrode was eaten away. It doesn't look like anyone has changed them in over 100,000 miles.

The plugs have been replaced, but the spark is still very weak, not bright blue like I would expect. I don't see any plug wires. I have a resistor pack and rubber boots together in one pack on top of the engine. Is there way to test if the that pack delivers proper voltage?

As far as the fuel system, my fuel pump activates, and I still have some pressure, as the fuel port in the injector squirts when I use a screwdriver. The check engine light stays on when the motor is being cranked. I don't know if it was lit up before. As far as I know, the light should go away once the engine is running. The crank sensor should turn it off. The computer isn't throwing any codes, and there were none saved. All systems check out when I hook up my reader. I suspect the crank sensor or wiring may be bad. Is there anything else that could cause this?

A: I think that the ignition coil is a very li...

I think that the ignition coil is a very likely cause of this issue. Since the spark plugs do not have their own individual coils, if the main ignition coil fails, it could affect all cylinders’ ability to spark.

This part is also a fairly common failure on this engine. To be honest, this is somewhat of a poor design of ignition system due to the probability of failure and the problems that can be associated with just one part failing. General Motors offers a diagnostic test for this ignition coil using either a GM scan tool or a digital multimeter.

For best results, have the ignition coil tested by a certified mechanic to ensure that the readings are accurate and comprehended correctly. Once the coil has been tested, the mechanic would relay the results of the test over to you to make a repair decision, which may include replacing the ignition coil, if deemed necessary.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: The car hesitates at higher speeds, check engine light on

You need to have the Check Engine Light code diagnosed to see if you have a problem. I feel the person that checked you car was trying to sell you a service that you may not need instead of looking...

Q: front right wheel making whistling/scraping sound.

Hi there. It is possible that the brakes can be causing this. If they are worn out prematurely then this will occur. It may also be a failing hub bearing. I have replaced both of these on this car for...

Q: Sometimes it starts, sometimes it doesn't.

Hi there. This does sound like a voltage issue. I would start by doing a load test of the battery and the alternator. Most of the time it is a battery issue. I would also check the connections at the...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...