6pc Diesel Fuel Injector Cap/ Block-Off Tool Chevrolet GMC Dodge Cummins Duramax
About this item
Set
Of 6 Pcs
Diesel
Fuel Injector Cap/ Block-Off Tool
for
2001-2005
6.6L Chevrolet/GMC Duramax applications (LB7 & LLY) and 2003-2007 5.9L
Dodge/Cummins applications
This diesel fuel injector cap/block-off tool set is
a toolbox essential for everyone working on Duramax, GMC, and Dodge/Cummins
fuel systems.
When a diesel engine fails to start, your first
troubleshooting step should be to check fuel rail pressure. If the pressure is
low, the most likely culprit is a defective diesel fuel injector returning
excess fuel back to the tank. A return flow volume test will allow you to
determine if excessive fuel return flow is the issue.
To identify the individual cylinder that is at
fault, you will use this cap/block-off tool. The diesel fuel injection line is
removed from one cylinder at a time and the cap is then installed on the fuel
rail in place of each injection line. When the bad injector is blocked off, the
fuel pressure at the rail will increase and your engine will start.
In some situations, it can be useful to have
multiple block-off tools, because multiple diesel injectors returning a small
amount of diesel fuel will display the same symptoms as an individual diesel
injector returning an excessive amount of fuel.
The diesel injector cap tool can also be used for
diagnosing engine knocking sounds that could possibly be caused by a diesel
injector or a single cylinder issue, especially on engines where you can't use
a scan tool or if a scan tool is unavailable.