Your cart is empty.
Your cart is empty.When a Cummins common rail engine will not start, the very first thing to check is fuel rail pressure. If the pressure is less than 5,000 PSI, one of the most likely causes is a defective injector that is returning excess fuel back to the tank. A return flow volume test will verify if excessive return flow is the problem. This cap is then used to identify the individual cylinder that is at fault. The injection line is removed for one cylinder at a time and the cap installed on the fuel rail in place of the injection line. When the cylinder with the offending injector is capped, the rail pressure will rise and the truck will start. In some cases it can be highly advantageous to have multiple caps, because several injectors that return slightly too much fuel can have the same effect as a single injector with extremely excessive return flow. To purchase a complete set of block off tools, please see our other Amazon listings. The injector block off tool can also be useful for diagnosing engine knocking sounds that may be attributable to an injector or a single cylinder problem particularly on engines where this capability is not available through the scan tool, or a bi-directional scan tool is not available. At least one of these would also be a great addition to the glovebox kit of every Cummins owner. When an injector malfunctions on a common rail engine damage to a piston or cylinder can occur very rapidly. When a common rail engine begins to misfire and blow excessive white smoke, the owner is highly advised to turn the engine off and call a tow truck to prevent major engine damage from occurring. An alternative would be to temporarily cap the injector for that cylinder for a short period. When working on high pressure fuel systems, always educate yourself first by reading appropriate factory service information, use common sense, and, above all, WEAR SAFETY GOGGLES!
cprivard
Reviewed in the United States on April 18, 2021
Worked for checking injectors to see which were bad perfect fit
Eli
Reviewed in the United States on October 20, 2020
This made troubleshooting the diesel so much easier, better and safer than trying to weld up an old fuel line to make a cap.
Customer
Reviewed in the United States on August 5, 2019
Does great
Chad Holder
Reviewed in the United States on June 12, 2019
Fast shipping! So that I could get back on the road. Was able to identify the fouled injector on my 2006 Cummins HPCR. If you are experiencing excess white smoke at start up (my symptoms) you need to use this to identify which injector is bad! Looked it up on YouTube and was able to order a new Injector and install it within 4 days. Will order more to have on hand!
Robert Bishop
Reviewed in the United States on May 19, 2019
Did okay
Casey
Reviewed in the United States on November 7, 2018
Worked perfect. Was able to isolate the bad injector right away.
Hoyt
Reviewed in the United States on December 3, 2017
Great insurance to carry.
Customer
Reviewed in the United States on July 13, 2016
prompt delivery and quality product
Recommended Products
