Troubleshooting a no-start problem is easier than you think. I can tell you, from personal experience, that there is a method with madness of troubleshooting a no-start problem.
In this tutorial you'll find a primer on how to diagnose a no-start problem. I'll explain the diagnostic flow that's used to find out what's causing the engine to not start.
Contents of this tutorial:
- Difference Between A No-Start And A No-Crank Condition.
- Engine No-Start Diagnostic Basics.
- What Tools Do I Need?
- STEP 1: Testing The Ignition System For Spark.
- STEP 2: Testing The Fuel Pump's Pressure.
- STEP 3: Making Sure The Engine Has Good Compression.
- STEP 4: Checking For A Blown Head Gasket.
- No-Start Troubleshooting Summary.
- More 3.3L V6 Buick, Oldsmobile Tutorials.
APPLIES TO: This tutorial applies to the following vehicles:
- 3.3L V6 Buick Century: 1989, 1990, 1991, 1992, 1993.
- 3.3L V6 Buick Skylark: 1989, 1990, 1991, 1992, 1993.
- 3.3L V6 Oldsmobile Achieva: 1992, 1993.
- 3.3L V6 Oldsmobile Calais: 1989, 1990, 1991.
- 3.3L V6 Oldsmobile Cutlass Ciera: 1989, 1990, 1991, 1992, 1993.
Difference Between A No-Start And A No-Crank Condition
Before we get going, I want to explain the difference between a no-crank problem and a no-start problem.
In a no-crank problem, the starter motor has stopped functioning and does not turn the engine over.
In a no-start problem, the starter motor works just fine, it's just that no matter how much it turns over the engine, the engine is not going to start.
So, if you're trying to troubleshoot a no-crank problem, this tutorial won't help you. What I recommend is that you start by testing the starter motor.
Engine No-Start Diagnostic Basics
The issue causing an engine no-start problem usually boils down to one of the following:
- The engine is not receiving fuel.
- The engine is not receiving spark.
- The engine has a compression problem.
Knowing this is the secret to testing and successfully resolving a no-start problem.
To drive the point home, the engine needs 3 things to start:
- Air (Compression).
An engine no-start problem will be caused by a lack of one of those three. Knowing this, is a tremendous time and money saver when troubleshooting the cause of an engine's no-start problem.
This also means that we can perform 4 basic tests find out what's causing the engine to not start:
- Ignition system test: spark test.
- Fuel system test: fuel pressure test.
- Engine compression test.
- Blown head gasket test.
In the following subheadings you'll find a basic testing guide that you can use to find out what's behind your 3.3L V6 Buick or Oldsmobile's no-start problem.
What Tools Do I Need?
A no-start problem cannot be troubleshooted without a few basic but important tools.
- A spark tester.
- A fuel pressure tester.
- An engine compression tester.
- A multimeter.
- A code reader.
For the ignition system spark tests, I'm going to recommend that you use an HEI spark tester.
This is the most accurate spark tester that you can buy and it doesn't cost an arm and a leg. You can find out more about it and where to buy it here: HEI Spark Tester (at: easyautodiagnostics.com).
You'll notice that I didn't include a scan tool in the list. But if you have one, I can tell you that it'll come in handy. Why? Because some of the components that cause a no-start condition can leave a specific trouble code (when they fail).
In this tutorial I haven't included it (a scan tool) in any of the suggested tests because they can be done without one.
STEP 1: Testing The Ignition System For Spark
To get your no-start diagnostic underway, it's important that you first start by making sure that the ignition system is producing and delivering spark to the spark plugs.
Testing the ignition system involves making sure that all 6 spark plug wires are sparking.
It's very important that you use a dedicated spark tester to test the spark plug wires for spark. The spark tester I recommend the HEI spark tester.
Using any other method that does not involve a dedicated spark tester, to test for spark, will have you chasing ghosts. Worst of all, you'll end up wasting time and money replacing good parts that don't solve the problem.
The ignition system is NOT causing the no-start problem if:
- Spark is present at all 6 spark plug wires.
With all 6 spark plug wires delivering spark to the cylinders (spark plugs), you can conclude that the ignition system is NOT causing the engine no-start problem.
You can also conclude that:
- The crankshaft position (CKP) sensor is good.
- The ignition control module (ICM) is good.
- The ignition coil pack is good.
Since the ignition system is creating and feeding spark to the engine cylinders, the next test steps are to test the fuel pump's pressure. Go to: STEP 2: Testing The Fuel Pump's Pressure.
The ignition system IS THE CAUSE of the no-start problem if:
- You got NO spark at all 6 spark plug wires.
The components that can cause this no-spark problem are:
- A bad crankshaft position (CKP) sensor.
- A bad ignition control module (ICM).
- In some rare cases, a bad ignition coil pack.
Your next steps are to:
- Test the crankshaft position (CKP) sensor (to make sure that the ignition control module is receiving a CKP signal).
- Test the ignition control module (ICM).