No Start 1: Checking For Spark
The ignition system on the Quad-4 engine is infamous for causing a lot of problems and my suggestion is to start checking here first.
I know that testing the Quad-4 ignition system can seem quite daunting, but it is testable and you can find out if the problem that making your car not start is being caused by an ignition system component.
To get into more specifics, the idea here is to make sure that all 4 cylinders are getting spark and that the components that provide this spark are OK. These components are the: spark plugs, spark plug boots, ignition coil cover, and the ignition coils.
The following tutorials will help you test the ignition coils in a step-by-step manner:
- How To Test The Ignition Coils GM 2.4L Quad 4 (at: easyautodiagnositcs.com).
- How To Test The Ignition Module & Crank Sensor (GM 2.4L) (at: easyautodiagnositcs.com).
- Diagnosing A Bad Ignition Coil Quad 4 Case Study (at: easyautodiagnositcs.com).
No Start 2: Checking For Fuel
The most common problem with the fuel system that'll cause a no-start problem is a bad fuel pump.
Checking that the fuel pump is delivering fuel to the fuel injectors on your Quad-4 equipped GM car requires a fuel pressure gauge with the correct adapter to tap into the fuel pressure line.
Another method that I've used to test for a lack of fuel, is spraying starting fluid into the throttle body and then having a helper crank the engine. If the engine starts, then I now know that I need to take a closer look at the fuel pump to see if it's fried or not.
When testing the fuel pump (with a fuel pressure gauge), you'll usually see one of two results:
CASE 1: Fuel pressure is at specification. Not only does this result tell you that the fuel pump is OK but that the following components, that supply the fuel pump with power, are OK too:
- Fuel pump fuse.
- Fuel pump relay.
And so, there's no need to spend time testing them or money replacing them.
CASE 2: Fuel pressure is not present. This usually means that the pump has failed, but not always. I would recommend testing/checking the following before condemning the fuel pump:
- After verifying that no fuel pressure exists, check that the fuel pump is getting power by tapping into the power circuit that feeds the pump with 12 Volts with a multimeter.
- Once you're tapped in, have a helper crank the engine while you observe your multimeter in Volts DC mode. If voltage is present (12 Volts), then you have confirmed that the fuel pump fuse and fuel pump relay are working perfectly.
- Confirming power to the fuel pump (with a multimeter) also verifies that the fuel pump has failed and needs to be replaced.
- If no voltage is present, as your helper cranks the engine, then the cause of no-fuel condition is due to either a bad fuse, fuel pump relay (known as the Main Relay).
No Start 3: Checking Engine Mechanical Condition
One of the most overlooked areas, when testing a hard to diagnose no start, is the mechanical condition of your Quad-4 equipped GM car vehicle.
Checking the engine mechanical condition usually means making sure that the timing belt hasn't broken (if equipped with a timing belt). Also, you may need to do: an engine compression test, a blown head gasket test, among a few tests to make sure that an internal engine problem is not the root cause of the cranks but does not start condition your vehicle is experiencing.
The following tutorials will help you do a compression test and a blown head gasket test:
- How To Test Engine Compression (GM 2.4L Quad 4).
- How To Test For A Blown Head Gasket (GM 2.4L Quad 4).
No Start Summary
By this point, in this tutorial, you now know that the cranks but does not start condition of your Quad-4 equipped GM car is due to a lack of one of the following:
- Spark.
- Fuel.
- Air (from a lack of cylinder compression).
Also, that you can verify if these things are missing or not, which means that you can: test for spark,, you can test the fuel pump (fuel pressure), and you can test the engine compression.
Thankfully, all of these things can be tested with simple tools, which leads me to the next talking point -to check the basics, you need tools.
There's just no way around it. One of the analogies that I've always enjoyed repeating, about doing a job without the right tools is like trying to eat a bowl of soup with a fork.
So besides knowing what to test, you need tools to do those tests. You don't have to spend an arm and a leg, since you can buy a lot of diagnostics tools that are tailored for the pocket-books of the serious do-it-yourself-er. Here are some of the basic tools you'll need:
- Fuel pressure gauge.
- Spark tester.
- Compression gauge.
- Multimeter.
Most of these tools you can buy or rent for free (after you leave a cash deposit which you'll get back when you return the tool) at your local auto parts store (mainly AutoZone and O'reilly Auto Parts). Or, if you want to save some bucks, you can buy them online.
Related Test Articles
You can find a complete list of tutorials here: GM 2.4L Index Of Articles. Below, is a sample of articles you'll find in this index of articles:
- How To Test For A Blown Head Gasket (GM 2.4L Quad 4).
- How To Test Engine Compression (GM 2.4L Quad 4).
- How To Test The MAP Sensor (GM 2.4L Quad 4).
- How To Test The Fuel Injectors (GM 2.4L Quad 4).
- How To Test The Ignition Coils GM 2.4L Quad 4 (at: easyautodiagnositcs.com).
- How To Test The Ignition Module & Crank Sensor (GM 2.4L) (at: easyautodiagnositcs.com).
- Diagnosing A Bad Ignition Coil Quad 4 Case Study (at: easyautodiagnositcs.com).
If this info saved the day, buy me a beer!
