PLEASE FOLLOW THE BELOW INSTRUCTIONS PRIOR TO FITMENT OF
DELPHI COMMON RAIL INJECTORS
It has been found across a wide range of vehicles using DELPHI solenoid fuel injectors that once the
injectors have been removed and refitted (whether due to an injector related issue or after the injectors
have been removed for other engine related repairs), the vehicle may develop an engine miss, run poorly
or may not start.
The problem arises from the injectors not being completely bled allowing engine compression to enter
through the injector nozzle orifices. The carbon deposits impede the operation of the internal components
which results in the poor performance and/or the vehicle not starting.
To ensure the fuel system is adequately bled prior to cranking the engine, please follow the below steps.
NOTE: The fitment instructions are for solenoid actuated injectors only. Do NOT follow the below steps if
the injectors are piezo actuated. DELPHI piezo injectors can be identified by having no backleak.
When working on vehicles and replacing injectors, the battery (or batteries) must be disconnected as
the ECU will retain memory of the previous state and fail to relearn the operational characteristics of
the replacement injectors once installed. Disconnect the battery for a period greater than 5 minutes
Reconnect the battery
3. Code injectors to the ECU prior to fitment to the engine
Fit the injectors without tensioning the fuel inlet pipe (approx. ⅓ turn from tight). Leave the injector
harness connectors disconnected
5. Disconnect harness plug to IMV (Inlet metering valve) on the high pressure pump
6. Crank engine to build fuel pressure to the injectors without starting
Once the fuel has been bled to the injectors;
7. Tension the high pressure pipes to the correct torque specifications
Using a scan tool confirm the rail pressure whilst cranking to ensure that the pressure is above 30 MPA
9. Reconnect harness plug/connectors to the IMV on the high pressure pump and to the injectors
10. Start engine
11. Test drive vehicle. It is also recommended that the vehicle is given at least one full day of running
through a range of operational conditions to allow the replacement injectors to learn the new
Posted May 23, 2022