No start after fuel injector change. 2008 Cadillac CTS 3.6 DI?

After using a diagnostic scanner and coming up with codes suggesting bad injectors “fuel injector group c..group d..dtc no definitions found”stuck open” I replaced them and attempted to start it with no success. It seems like there is no change in starting rhythm although it will crank smoothly for a second during a cold start and then shut off before the engine ignites. I know that replaced fuel injectors and still no start might indicate dirty fuel, bad fuel pump, filter, etc but Is there some type of protocol that needs to be addressed after changing injectors that I’m missing ? Any advice would be helpful thank you 

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  • Anonymous
    1 month ago

    No start AFTER fuel injector change.

    Was there start BEFORE the fuel injector change? 

    Make sure the fuel injectors have +12 volts on them when the ignition is on.  I have seen people break the supply wire in the wiring harness.  Did you unplug a wiring harness connector?  Make sure the connector is making contact. 

    Maybe use some noid lights to make sure the computer is grounding them.

    Make sure you have adequate fuel pressure at the fuel pressure test fitting on the fuel rail. 

    Check for spark too.

  • 1 month ago

    I would be questioning the fuel pressure above anything else.Harbor Freight sells an inexpensive pressure tester that connects to the fuel rail which will eliminate the guess work

  • Anonymous
    1 month ago

    Check if the injectors are firing while cranking.  If they are not firing, check for power and ground to the injectors with a noid light.  Could be just a bad injector fuse or a bad ground.  Good luck.

    https://www.youtube.com/watch?v=n0s6ST_InEg

    Youtube thumbnail

  • 1 month ago

    There are some fuel injectors that are numbered they have a number and you can only use them in the port with the corresponding number. If you have that kind of fuel injectors then you might have accidentally put them all in the wrong holes not knowing that they were numbered to correspond with the chip and the computer.

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  • Anonymous
    1 month ago

    well - of course one of the first things to check is whether you have fuel in the rails. there are usually bleeder valves on them to check this. be careful - if there is gas in there it may be under high pressure

  • 1 month ago

    You should never just go spend the money replacing fuel injectors without further diagnosing the codes. I'd suggest trying to take the battery cables off the battery and holding them together for a minute with hopes that will help the no start. You need the fuel pressure checked and it wouldn't hurt to take a fuel sample in a mason jar to find out if there's any water or dirt in the gas.

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