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Car running fine. next mornig, running very rough. Code test tool says "Open circuit Fuel Injector 4" 1. Is this a fuel injector replacement issue? Or could it be a simpler electrical circuit issue? 2. Is there any way to test the above question? 3. If it is an injector, is there any way to clean or otherwise fix the issue without a replacement injector 4. If it is likey an electrical issue, what would be the most likely culprit? Loose wire or other wiring related quick-fix type problems. Or would it be some other more complicated and more challenging to fix electrical circuit testing issue? 5. Last question: If it is a fuel injector replacement issue, do I need anything in addition to a reman. injector? Do I need to buy an O-ring kit also? Anything else I might need (special tool, a step-by-step guide becasue it is a tricky replacement perhaps?) Qualified help to answer these question would help me keep my wife (told me it was a dumb car to buy), keep my job (I need relaible transportation as a requirement for my job), and help me keep my friend (help him keep his wife around) who is loaning me a car (against the wishes of his btchy wife). (backup) or work email

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1. This is a problem with either the injector or wiring.
2. You need a multimeter to test the electrical wiring in the injector and then the loom.
3. If it is an open circuit in the injector the only way around it is to replace the injector,these are not able to be repaired.
4.If it is an electrical issue then you need to trace the wiring back to the main connector in the engine bay, and check the wiring for continuity, if thats ok then you need to check the wiring from the main connector to the ECM. If this is ok then the fault will be in the ECM which you will need to replace. Check ECM output voltage to the injector with the key on, if it measures more then 4.5 volts across the wiring then all the wiring is ok. You will need to replace the injector.
5. Yes it will pay to replace the o-ring but it is only 1 oring so it shouldn't be that expensive, also you don't need any special tools just a good set of open end spanners etc.

So check the voltage to the injector first.
Then check the injector windings, then the wiring.......
Hope this helps, let me know if you need more information.



Posted on Sep 16, 2010


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