Injector driver failure?

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Jun 15, 2018 | 08:19 PM

bpdchief

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From: New Mexico

Injector driver failure?

Rebuilt a S5 T2. Discovered the rear primary is not delivering fuel. Initially thought it was a poorly wired injector clip and it was replaced with a new clip. Same problem. I should mention that injectors were cleaned and flow tested when engine was being rebuilt. Pulled injectors and tested per FSM. Front flows, rear doesn't. Switched front injector to rear and rear doesn't flow. I'm suspecting two things. Wiring issue somewhere in the harness or bad injector driver in the ecu. My question is this, does each primary injector have its own driver or are they powered separately? Can this be easily fixed or does the ecu need to be swapped out? Any advice is appreciated.

Jun 16, 2018 | 10:15 AM

j9fd3s

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From: https://www2.mazda.com/en/100th/

next step is to check injector voltage at the ecu. the ECU is the ground, so each injector should have 12v at the ecu, with the key on engine off. if that is ok, then it could be a driver, but you might want to check codes too, the JDM ecu in a US car will not run on the rear rotor because our mileage switch is their speed limiter, so its worth a look.

i believe since its sequential injection each injector will have its own driver, but i don't really know.