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Short Pulse Width Adder Values

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I have a set of ID1050s and the associated data from ID. The adder table has negative values (ms) in it which is confusing me. My understanding was that the ECU should be commanding an increase in IPW during low pulse width operation to bring up the flow to be more linear, but negative adders would be doing the opposite, right?

I've answered a similar question before on the Link forum so im just going to copy and paste here, hopefully it works:

Thanks for the help! I see where it can go negative at certain ranges, however in my 1050X data from ID, the entire range is negative, even below the knee and that is what I really confusing me. Here is the data I am looking at: Link G4 ID1050X Data

Link 1050X Data

Why so negative about negative numbers? They are the correction for short pluses that is required. It's just a number. Or put in 0, and just bake the error into the tune, that's what we did for years before all this Short Pulse correction, and injector calibration gave us more accurate control of injector performance.

I am just attempting to wrap my head around why there would be a decrease in injector pulse width a low IPW operation since my understanding would call for the opposite. Yes, of course it could be corrected for in the tune, but I am not trying to figure out a way around it, just understand it.

A negative SPWA just means the injector is flowing more than an ideal or perfectly linear injector would. So you would have to shorten or subtract PW to achieve the correct dose. At short PW's injectors become non-linear, there is no longer a strict relationship between PW and flow and the variation can be in any direction.

I haven't personally tested an ID1050X, but below is the closest example I have to an injector that has mostly negative SPWA:

As others have mentioned, many injectors require negative non linear compensation values.

Non linearity is simply deviation from linear behavior, so it can go in either direction, and often a bit of both depending on the portion of the range you're looking at.

The ID data for 1050x does provide appropriate results, so you'll be in good shape.

I have been out of town, but wanted to come back and just thank everyone for taking the time to help me out with this. I genuinely appreciate it. This has been nagging me for a while, but thanks to all of you, I finally have it figured!

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