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Injector Dead Time

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Hi,

I thought about a solution to injector dead time scaling and I was curious to see if my solution is incorrect. Often times when you are dealing with injectors, the data is incorrect or missing and often the only "known" characteristic is the flow rate. Just like MAF/Injector Scaling I'd think the process would be similar. If the engine has been tuned with stock injectors with obviously correct data (amongst other parameters), then the VE Table (correctly tuned) will be accurate. If we then switch to different injectors, and the Lambda differs from target we then know for a fact that the injectors need scaled.

So, if we know for a fact that either the injector flow rate, OR the injector dead time is accurate, we can scale each one. If we know at least one of the two are accurate, then we can simply modify that one parameter until we reach our target lambda. In other words if all of the variables in the equation are accurate, except one we can solve to find it.

Another clever trick to isolate injector dead-time only calibration. If the ECU can run batch injection (ie, each injector fires once per revolution -- that is twice per cycle), as well as sequential injection (once per cycle). Then you can just idle (or any other way to hold a fixed RPM) the engine and change back and forth, tuning the injector deadtime until there is no difference in measure Lambda.

All error would be due to the dead time being wrong for either one or two pulses. If the batch is richer than the sequential, the deadtime is too short. If the sequential is richer than the batch, then the deadtime is too long.