OP what do you mean Enthalpy "erased the code"? Couldn't that have been achieved with an OBD scanner or simply disconnecting the battery? Or did he disable the knock sensor circuit? curious..
Quote:
Originally Posted by Croustibat
Didn't saw that answer at the time...
Ask any tuner using a nistune, and he will tell you are wrong. The ECU has 2 sets of fuel & timing maps, when it detects knock it uses the alternate knock maps (and may pull timing on top of that, many users reported this when copying normal maps to knock maps). Or you could just seach the internet for the ECU address file. You will see there are 2 sets of maps. If you are still not convinced, reverse engineer the ecu code. It is an old and simple mcu, so while tedious, it still is easy.
Anyway, mail order tune have their limits and injector modification is not that easy, esp. with a different FPR. Either your injectors are actually bigger than you think, and have a shorter latency than what is in the tune, or you may have a problem with the FPR, or ... the mail order tune is actually very rich on purpose, as no one wants a blown engine because the fuel system is weak.
It is not hard nor to set latency and K correctly, but the tuner really needs the car to get it spot on. It cannot be done without.
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I think you might be confusing the functionality of the knock sensor on reflashed ecu's. I wouldn't doubt that those might have additional fuel maps and features should the knock sensor encounter any issues.
I'm not completely ruling out the possibility that Nissan designed the stock ecu's with two fuel/timing maps, but I just have a hard time believing that they wouldn't have mentioned it in the FSM. Case in fact: My engine was producing devastating knock on boost which ended up cracking ring lands on #4 and there was no apparent change in the driveability. Even JimWolf himself told me that the knock sensor is there to retard timing under light loads and was mostly used to "protect" (although very minimal) the engine from bad gas, etc.