Dunno what they do but it works. It indexes the injectors so a set of them flow closer together than stock. I've used the the 90hp ones on marine QSB engines and they work perfectly with the stock programs on InCal. However I haven't had a chance to try them on the 480hp program yet.

Let me know if you want some of those castings

Can you describe this measurement and ECU calibration process?

Michael

At the time of manufacturing, each injector is measured for flow rate at a few different points. At each point, an offset is identified, relative to the nominal flow rate. There are a finite number of pre-defines offset "buckets" that each can be grouped into, at each point. These buckets are combined to form an identifier for the injector and turned into a 2D bar code (data matrix). The data matrix is laser etched onto the injector. This is then read at the factory and programmed into the ECU. This information is used as an offset in the nominal calibration to fine tune the amount of fuel delivered (per injector).

It's called IQA (Injector Quantity Adjustment). If you have an injector replaced at a dealership, the scan tool is used to reprogram the ECU to the correct IQA value for the new injector.

This is primarily an emissions function to remove variance in fuel delivered. The adjustment is small enough that performance isn't really impacted to measurable degree. There are other manufacturing variables that would have a bigger impact on total engine output.

That is VERY interesting. Thank you for such a detailed explanation. I guess the engineer in me is always curious about such things.

Michael

The little purpose built scanners and hopped up palm pilots can't do it. You need a laptop and INSITE to program with an INLINE adapter to load parameters into the ECU. And if you didn't download a template from somewhere. Or had the distributor e mail you one. Your gonna need the ICAL disc. Then after you load the template you can tweak the IQA manually if your using after market tuned injectors. Also a Redneck Special. On boats if you get out to some B.F. nowhere site and you don't have the right template boats usually have two engines just DL the template out of the good engine. With a little tweaking you'll git-er-done. When I get done setting a customer's boat I down load his ECMs and burn his templates on to discs. I make 3 copies. I give the customer 1 copy to keep (makes em feel good). I keep one for my files. One gets put in a DVD case wrapped in duct tape and stashed somewhere in the engine room. I kinda like behind the Smartcraft Control box. Also if your using an older template double load it. It might say its done after loading it once. We know them older templates always miss stuff on the first go around.

On GM product, you only need a Tech2 scan tool. This will let you tweak the IQA values. The problem is knowing what to tweak...the code looks like a random string of letters and numbers.

Worth noting is that IQA (in GM product) doesn't have a range of adjustment suitable for changing to aftermarket (bigger) injectors. It really is a fine tuning type of feature.

I be working on Cessie's stuff. With richer injectors just use the IQA range to level off the ouputs. The other data the ECM picks up will correct for the extra fuel. I had the problem with customers that beat their engines real hard cracking tips. When you compare the captured data between stock and richer injectors the ECM pulses more often and harder with the stock ones than the aftermarket ones. So the aftermarket ones hold up better because the're not getting beat as hard. Also as far as the actual IQA them ole boys @ DDP usually take from 50% to 75% of the difference in a set of injectors. The data is way easier to digest with Cummins INSITE system. But every time your turning around your buying a new disc.

http://www.harleyboats.com/

65 mph cruise? Must be some awful fast fish out there.