How to test a fuel injector for flow problems (GM)

This vehicle has an intermittent misfire that we are trying to locate. Here we will be focusing on the injectors, making sure they do not have any flow problems (restrictions or leaks)
An external timer tool will be used to fire the injectors at exact intervals while watching fuel pressure drops on a pressure gauge.
Since we cannot get to the injector connectors directly, we will be using a main bulk connector to access the injector control wires. This same procedure can be applied to many different systems.

Engine Performance Diagnostics chapter 18 page 26

Symptoms
- intermittent misfire
- check engine light (P0300 fault code)

Fix
- I don't remember but it wasn't the injectors :)

Tests shown
- injector balance test using an external timer tool

Tools used
- fuel pressure gauge/kit
- electronic fuel injector tester
- test light (LED or incandescent)
- jumper wires
- back-probing tools

Related videos
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How to identify injector flow problems (Toyota 1.8L) part 2
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How to test for injector flow problems (Dodge, Chrysler)
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Fuel injector flow testing (a free ScannerDanner Premium video)
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Playlist
- (Chapters 17, 18 and 19) Fuel Injector Testing
Playlist
   • (Chapters 17, 18 and 19) Fuel Injecto...  

For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
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