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How To Repair Denso Common Rail Injector-1

At present, the technical and maintenance information of Denso common rail injectors is widely used and existing in the global diesel market.

The following document aims to provide a guide to using the tooling and shim kits together with genuine and non-genuine parts, to strip, rebuild and test Denso ‘G2’ type common rail injectors.

Alterations to the shim adjustment of individual injectors were made and the results recorded. These results have been used to determine what effects any changes to the shim adjustment have on the overall performance of the injector.

Correction codes (QR codes) cannot be written and produced for any Denso injector using this information. The production and creation of QR codes requires complex software and intricate flow testing using genuine Denso/Hartridge authorised equipment.

Denso Common Rail injector repair involves stringent clean room practices and very tight quality control on build tolerances. Please take this into consideration when attempting any dismantling of Denso Common Rail injectors.

Hopefully this guide will provide an insight into what can be achieved with tooling available outside of the Denso official repair programme. Consideration should be given to the importance of correction codes when undertaking any adjustment or unofficial repair of ANY common rail injector that uses a correction code.

Component Overview and Identification:

The photo below shows an exploded stripped Denso G2 injector and labelled components:

Dismantling

The following dismantling, rebuild and test instructions are based on the use of the Common Rail injector kit (part number- 850901) and Shim Kits (850276, 850296, 850301) available to purchase from Diesel Distributors, together with genuine and non genuine repair parts.

STEP 1 – Solenoid Removal

Mount the injector upright in the vice using the correct holding jaws, depending upon the body type and using the 27mm ‘crow’s foot’ gently loosen the solenoid (fig 1). Once loose continue to loosen by hand and CAREFULLY and GENTLY remove the solenoid, taking care not to drop the solenoid valve spring or tensioning shim (Fig 2).

Remove the ‘fuel calibration shim’ that will either still be sat on the injector or sat up inside the solenoid body (Fig 2).

The solenoid valve can then be removed using long nose pliers. TAKE CARE NOT TO DROP THE ‘HALF BALL VALVE’(Fig 3). This is situated in the end of the solenoid valve. It is small and very easily lost!! -(Replacement valves and half ball valves are available through Diesel Distributors).