How to Replace an Injector in the Cummins 6.7L Engine

Updated on January 18, 2019
dieseldodge09 profile image

Dieseldodge09 has several certificates in diesel systems and engines.

Cummins 6.7L
Cummins 6.7L

Many of you out there do not know too much about the 6.7L Cummins Engine. Today, I am going to tell you how to replace an injector in the 6.7L fuel system.

Before you start, prepare your work station. Make sure your tools are ready and easily accessible. One very important thing: make a very clean area to lay the parts you are going to remove. Make sure you stay organized and keep it neat; don't just throw parts and bolts anywhere.

  • Disconnect the batteries.
  • Using a 11mm socket remove the clamps on the egr cross over.
  • Then remove the egr cross over tube. Unplug the connections to the egr valve and the connections to the intake flow valve.
  • Remove the boost tube from the intake plenum. Remove the first high-pressure fuel line from the connector tube and the hpcr. Using a 10mm socket, remove all the intake plenum bolts and remove the intake. Now you have more room to get to fuel lines and rail.
  • Now, with a 8mm socket, remove the top cover on the engine to gain access to the front valve cover bolts. Save and reuse this cover gasket.
  • Now, using a 10mm socket, remove the six bolts holding the valve cover down. Remove the valve cover and set aside. Now you will have complete access to the rockers and injectors.
  • Disconnect the injector harness from the main harness and, with a 8mm socket, remove the harness from the injector solenoids. Notice the injector harness doubles as the valve cover gasket. DO NOT DISCARD!
  • Depending on which injector you will be removing, you need to remove the exhaust rockers on each cylinder to access the injector hold-down bolts. Remember to put the rockers in order; don't mix them up so you wont have to set the valved lash later.

  • After you have removed the rockers, now locate the injector you need to remove. Remove the high pressure fue line from the HPCR and the connector tube to the injector with a 19mm.
  • Now remove the connector tube hold-down using a 24mm. Some connector hold downs are hard to get to; use a swivel if needed. Set the hold down aside.
  • Using a 8-mm socket remove the injector hold down bolts.
  • Pry up on the injector by using a clean well placed pry bar. There are several grooves in the injector that are suitable for this. There is not a lot of force needed to "pop" them out.
  • Remove the injector. Then remove the injector hold down from the injector because it will be used on the new injector.
  • Remove the new injector from the packaging and be as clean as possible.
  • Install the injector hold down on the new injector. Notice the groove in the rocker seat next to the injector hole. This is where the round part of the injector clamp will go; remember, the injector can only go into the clamp one way.
  • Write down the injector code so you can write it into the engine computer at the end.
  • Pay attention to the rounded and square collar on the injector clamp; the round side goes next to the rocker seat. Insert the injector and clamp into the port. Place a rag over the top of the injector and use some pressure to "pop" the injector down into its seat, you will hear and feel a definite "click" when it goes in.
  • Now with an inch-pound torque wrench, tighten the injector hold down to first 30 inch-pounds, then do final tightening to 79 inch lbs.
  • Now reinstall your the injector connector tube and tighten to 50 ft lbs.
  • Install your rockers and torque down them to 27 ft lbs.
  • Reinstall the injector harness and tighten all the nuts on the injector solenoids.
  • Reconnect the main harness to the injector harness.
  • Depending on how many injectors you have to replace, reinstall fuel supply lines starting with number 6 and working forward. Note that number 4 crosses over number 5 onto the fuel rail. Tighten the fittings.
  • Reinstall the intake plenum and connect the boost tube to the intake plenum. Now connect all your electrical connections to the EGR and intake.
  • Reconnect the connections that run across the valve cover's rear.
  • Reinstall the top cover. Reinstall the egr cross over tube and tighten clamps.
  • Now, using star scan, enter the injector trim code you wrote down that was stamped on new injector. Do not forget this step; the engine light will stay on if the wrong is code entered.
  • Now clear codes from unplugging sensors and you're done. Test-drive the truck to ensure proper operation.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.


    0 of 8192 characters used
    Post Comment

    No comments yet.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)