How To Test A Misfire / No Spark-No Start Condition (4.3L, 5.0L, 5.7L 96-04) How To Test A Misfire / No Spark-No Start Condition (4.3L, 5.0L, 5.7L 96-04)

This article will help you to find the cause of a misfire or No Spark- No Start Condition on your GM car, pick up, mini-van, van or SUV equipped with a 4.3L, or 5.0L, or 5.7L engine. The testing is explained step by step, making the whole diagnostic and troubleshooting as pain free as possible.

With the tests in this article, you'll be able to test and diagnose: A bad ignition control module, or a bad ignition coil, or a bad distributor cap, or bad spark plug wires. For a complete list of GM vehicles these tests apply to, take a look at the bottom of the page.

The following tutorials will also help you:

  1. How To Test The ‘Spider’ Fuel Injector Assembly (GM 4.3L, 5.0L, 5.7L) (at: troubleshootmyvehicle.com).
  2. How To Diagnose Misfire Codes (GM 4.3L, 5.0L, 5.7L) (at: troubleshootmyvehicle.com).
  3. GM Engine Compression Test (GM 4.3L, 5.0L, 5.7L) (at: troubleshootmyvehicle.com).
  4. How To Test The GM Distributor Mounted Ignition Module.

You can find this tutorial in Spanish here: Cómo Verificar el Sistema de Encendido (GM Vortec 4.3L, 5.0L, 5.7L) (at: autotecnico-online.com).

Symptoms Of A Bad ICM, Ignition Coil, Spark Plug Wires, Or Dist. Cap

If your GM car (or pick up, van , or mini-van) is suffering a misfire; the check engine light (CEL) will be on to let you know that YES, there really is something wrong. Here are a couple of other symptoms your vehicle may experience with a misfire condition:

  1. Diagnostic trouble codes (DTC) stored in the computer's (PCM) memory:
    1. P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308
  2. Misfire that does not light up the check engine light (CEL).
  3. No power.
  4. Idles rough.
  5. Bad gas mileage.
  6. Black smoke coming out of the tail pipe.
  7. Rotten egg smell coming out of the tail pipe.
  8. Smell of unburned gasoline coming out of the tail pipe.
  9. Won't pass the state emissions test.
  10. Cranks but doesn't start.

Basic GM Ignition System Theory

To successfully diagnose a Misfire or No Start on your GM car (pick up, van, SUV, or mini-van) it'll help to know how spark is created and fed to the engine cylinders. This is what happens, in a nutshell, when you turn the key and crank the engine:

  1. The crankshaft position sensor starts to generate and feed the PCM (Powertrain Control Module=Fuel Injection Computer) with its signal.
  2. The PCM uses this signal to know where each Piston is at in relation to its combustion cycle and with this info, the PCM knows when to start activating the ignition control module (ICM), activating the fuel injectors and a host of other things to get your vehicle started.
  3. So then, after receiving the crank (CKP) signal, the PCM sends the ignition control module (ICM) a Triggering Signal that tells the ICM exactly when to make the ignition coil spark. This Triggering Signal is known as the IC (Ignition Control) Signal in the GM service literature.
  4. The ignition control module now starts to open and close the primary current circuit of the ignition coil and as you may already be aware, it's this opening and closing action that makes the ignition coil spark away. This opening and closing action is referred to as the Switching Signal in this article.
  5. The spark created by the ignition coil is fed to the distributor cap by a high tension wire and from there to each engine cylinder by a spark plug wire.

With the simple and easy tests presented in this test article you'll be able to find the exact cause of your vehicle's misfire or no start condition (if it's ignition system related) and in the process save time and money.

Ignition System Diagnostic Manual Download

This tutorial has a lot of the information you'll need to diagnose and solve the ignition system problem causing your GM vehicle's no-start problem or a misfire problem.

But, if you'd like to have access to a wiring diagram, ignition component connector pin-outs, and the entire testing procedure in one place, then take a look at the following:

Chevrolet/GMC C/K Series Full Size Pick Ups:

Engines: 4.3L, 5.0L, 5.7L, 7.4L
1996 Full Size Pick Up
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagrams.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing orders.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 1996 Chevrolet C1500, C2500, C3500 Pick Up.
  2. 1996 Chevrolet K1500, K2500, K3500 Pick Up.
  3. 1996 GMC C1500, C2500, C3500 Pick Up.
  4. 1996 GMC K1500, K2500, K3500 Pick Up.
Engines: 4.3L, 5.0L, 5.7L, 7.4L
1997 Full Size Pick Up
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagrams.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing orders.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 1997 Chevrolet C1500, C2500, C3500 Pick Up.
  2. 1997 Chevrolet K1500, K2500, K3500 Pick Up.
  3. 1997 GMC C1500, C2500, C3500 Pick Up.
  4. 1997 GMC K1500, K2500, K3500 Pick Up.
Engines: 4.3L, 5.0L, 5.7L, 7.4L
1998 Full Size Pick Up
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagrams.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing orders.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 1998 Chevrolet C1500, C2500, C3500 Pick Up.
  2. 1998 Chevrolet K1500, K2500, K3500 Pick Up.
  3. 1998 GMC C1500, C2500, C3500 Pick Up.
  4. 1998 GMC K1500, K2500, K3500 Pick Up.
Engines: 4.3L, 5.0L, 5.7L, 7.4L
1999 Full Size Pick Up
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagrams.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing orders.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 1999 Chevrolet Silverado, C1500, C2500, C3500 Pick Up.
  2. 1999 Chevrolet K1500, K2500, K3500 Pick Up.
  3. 1999 GMC Sierra, C1500, C2500, C3500 Pick Up.
  4. 1999 GMC K1500, K2500, K3500 Pick Up.
Engines: 4.3L, 5.7L, 7.4L
2000 Full Size Pick Up
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagrams.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing orders.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 2000 Chevrolet Silverado, C2500, C3500 Pick Up.
  2. 2000 Chevrolet K1500, K2500, K3500 Pick Up.
  3. 2000 GMC Sierra, C2500, C3500 Pick Up.
  4. 2000 GMC K1500, K2500, K3500 Pick Up.

Chevrolet Express Van and GMC Savana Van:

Engines: 4.3L, 5.0L, 5.7L, 7.4L
1996-1999 Express/Savana
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagrams.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing order.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 1996-1999 Chevrolet Express Van.
  2. 1996-1999 GMC Savana Van.
Engines: 4.3L, 5.0L, 5.7L, 7.4L
2000 Express/Savana
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagrams.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing order.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 2000 Chevrolet Express Van.
  2. 2000 GMC Savana Van.

Chevrolet Tahoe and GMC Yukon:

Engines: 5.7L
1996-2000 Tahoe/Yukon
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagram.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing order.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 1996-2000 Chevrolet Tahoe (4x2 and 4x4).
  2. 1996-2000 GMC Yukon (4x2 and 4x4).

Chevrolet and GMC Suburban:

Engines: 5.7L, 7.4L
1996-1999 Suburban
Ignition System No-Start Diagnostic Manual

$3.99 USD

 

All of the information you need to diagnose a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

Diagnostic manual comes with:

  1. Wiring diagram.
  2. Component pin outs.
  3. Connector pin outs.
  4. Ignition system component part numbers.
  5. Firing order.
  6. Complete step-by-step testing instructions.

The illustrations in the diagnostic manual are printer friendly! Applies to:

  1. 1996-1999 Chevrolet Suburban (4x2 and 4x4).
  2. 1996-1999 GMC Suburban (4x2 and 4x4).
Chevrolet Vehicles:
  • Astro
    • 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • Blazer
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • Blazer TrailBlazer
    • 1999, 2000, 2001
Chevrolet Vehicles:
  • C1500, C2500, C3500 Pick Up
    • 1996, 1997, 1998, 1999, 2000
  • Express Van 1500, 2500, 3500
    • 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
  • G30 Van
    • 1996
  • K1500, K2500, K3500 Pick Up
    • 1996, 1997, 1998, 1999, 2000
Chevrolet Vehicles:
  • K1500, K2500 Suburban
    • 1996, 1997, 1998, 1999
  • P30 Van
    • 1996, 1997, 1998, 1999
  • S10 Blazer
    • 1994
  • S10 Pick Up
    • 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
Chevrolet Vehicles:
  • Silverado 1500 Pick Up
    • 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007
  • Tahoe
    • 1996, 1997, 1998, 1999, 2000
GMC Vehicles:
  • Sierra C1500, C2500, C3500
    • 1996, 1997, 1998, 1999, 2000
GMC Vehicles:
  • Suburban C1500, C2500
    • 1996, 1997, 1998, 1999
  • G3500 Van & Vandura
    • 1996
  • Jimmy & Envoy
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • K1500, K2500, K3500 Sierra
    • 1996, 1997, 1998, 1999, 2000
GMC Vehicles:
  • P3500 Van
    • 1996, 1997, 1998, 1999
  • S15 Jimmy
    • 1994
  • Safari
    • 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
GMC Vehicles:
  • Savana Van 1500, 2500, 3500
    • 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
  • Sonoma
    • 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
GMC Vehicles:
  • Yukon
    • 1996, 1997, 1998, 1999, 2000, 2001, 2002
Isuzu Vehicles:
  • Hombre
    • 1997, 1998, 1999, 2000
Oldsmobile Vehicles:
  • Bravada
    • 1996, 1997, 1998, 1999, 2000, 2001
Cadillac Vehicles:
  • Escalade
    • 1999, 2000