Quote:
Originally Posted by SAM@GTM
You covered a lot of it. There's really multiple definitions of a "bad injector" it could cause the car to run on 5 cylinders, the exhaust will be popping, rough idle, also our cars equipped with 7 different misfire codes. There's a P0300 that covers random misfire, then there is P0301 - p0306 which is cylinder specific misfire. If Eric's car had a bad injector on a specific cylinder, a specific code would have been present.
Making the statement that the car had a bad injector and that is why the car was detonating is such a blanket statement and is inaccurate. We spent 20 hrs diagnosing this particular car and logging all the ECU parameters via Cipher and Nissan's ConsultIII Factory Diagnostic Tool. At no point was there any indication of one bad injector. If you have a bad injector on one of the banks of the engine, your correction factor will be different since one wideband on a particular bank will read richer or leaner. Eric's car did not have that symptom.
If you have a bad injector, you will have a rich or a lean code since the bad injector will spray too much or not enough fuel which will alter the AFR target. The factory ECU pays very close attention to the correction factor and the differences between bank 1 and bank 2. The minute it sees any serious variation, it will throw a code.
Another indication of knowing whether you have a problem with a particular cylinder with a bad injector is to remove and check the spark plugs. This is an old fashioned way of getting a clear idea of how your combustion chamber is operating. If you remove the spark plugs and they all have a similar brownish color, that is an indication of a nice healthy combustion. When you have a bad injector, you'll notice that particular spark plug will be extremely white from running lean, or extremely black from running excessively rich.
Now if we start talking about spray pattern, this will open up a completely different front. Keep in mind that the DW injectors are modified Denso injectors although they will never be perfect like an OEM factory unmodified injector.
As far as why Eric's car was not running properly, the information was shared with Eric and I was very tempted to really share all my logs and the things I found, but I did not want to start a shitstorm, so I left it alone.
Sam
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Since you decided to chime I would like to ask you this about Erics car. In your thread that you maid you mentioned that you could not get a ccurate air fuel at the tail pipe why check there in the first place? Also when you put the bung in the correct location and saw AFR of high 13's did you try and tune the car? to confirm 100 percent that the kit had design flaws.
Now I know what some of the flaws are with this kit if your trying to make a decent amount of power. But at Eric's power level I really dont see a reason why it wouldnt work with a good tune. Witch i know your more than capable of your one of the best tuners in the country.