Hello everybody,Firstly please excuse me for my bad english, I m from France.I have got a 91 NSX and I had an injector died. I bought 6 new ones from USA which are 350cc, OEM qre 240cc or 260cc.My problem is the following : I have now too much petrol in the engine at idle.I bought also a green filter to let nore air get in the engine.Now I m looking form someone who could remap the ECU to fit to the new 350cc injectors.I have already read the flash in the ECU so I can place it in the forum.Thx a lot in advance for any help.
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Welcome to NSX Prime!
If you haven't seen it, sr5guy uploaded a "definition" with which you can decode the values in the OEM PGM-FI. See here: http://www.nsxprime.com/forum/showthread.php/186602
From what I understand, simply multiplying all the injector duration values by 69% (240cc / 350cc) is not the best way to tune for new injectors. Different models of injectors take different lengths of time to open and to close, which impacts how long the "open" signal should be in order to inject a certain volume of fuel. Differences in "injector latency" impact the volume of fuel injected more the shorter the "open" signal is. Different injectors can also atomize the fuel differently, which impacts how quickly the fuel burns. So dialing in the PGM-FI properly for new injectors requires more than just multiplying all the injector duration values by a certain fixed percentage.
To tune your PGM-FI well, you should probably have the latency of your injectors measured at different voltages (there is a map for that in the PGM-FI) and then take your car to a tuner to adjust the injector duration and ignition maps with your car on a dyno and wideband oxygen sensors in the exhaust. Using sr5guy's "definition" running in the program TunerPro RT and with a Moates Ostrich 2.0 emulator hooked up to a laptop computer, any competent tuner should be able to do that.
However, given the effort involved in tuning the PGM-FI properly for the flow rates, latencies, and atomization of new injectors, it would be much cheaper to just replace your one dead OEM injector with a new one, have all six OEM injectors ultrasonically cleaned, and reinstall those.
Is your NSX a European 1991? If so, I'd love to see the OEM .bin file you've read out of the PGM-FI. Sr5guy uploaded US .bin files in the link above and it would be really interesting to see whether EDM NSXs used the same maps.
If you haven't seen it, sr5guy uploaded a "definition" with which you can decode the values in the OEM PGM-FI. See here: http://www.nsxprime.com/forum/showthread.php/186602
From what I understand, simply multiplying all the injector duration values by 69% (240cc / 350cc) is not the best way to tune for new injectors. Different models of injectors take different lengths of time to open and to close, which impacts how long the "open" signal should be in order to inject a certain volume of fuel. Differences in "injector latency" impact the volume of fuel injected more the shorter the "open" signal is. Different injectors can also atomize the fuel differently, which impacts how quickly the fuel burns. So dialing in the PGM-FI properly for new injectors requires more than just multiplying all the injector duration values by a certain fixed percentage.
To tune your PGM-FI well, you should probably have the latency of your injectors measured at different voltages (there is a map for that in the PGM-FI) and then take your car to a tuner to adjust the injector duration and ignition maps with your car on a dyno and wideband oxygen sensors in the exhaust. Using sr5guy's "definition" running in the program TunerPro RT and with a Moates Ostrich 2.0 emulator hooked up to a laptop computer, any competent tuner should be able to do that.
However, given the effort involved in tuning the PGM-FI properly for the flow rates, latencies, and atomization of new injectors, it would be much cheaper to just replace your one dead OEM injector with a new one, have all six OEM injectors ultrasonically cleaned, and reinstall those.
Is your NSX a European 1991? If so, I'd love to see the OEM .bin file you've read out of the PGM-FI. Sr5guy uploaded US .bin files in the link above and it would be really interesting to see whether EDM NSXs used the same maps.
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