95 lt1 injector offset questions

[kur4o]

I see you are out of ideas, so why don`t you jump in and give it a try of the ls injector patch. Anyway you already have the needed cal data.

When I put the ls injectors I figured that is not possible to interpolate the tables good enough, and since ls injector data is superior to anything gm have done previously I just made the patch to utilize the improved ls inj data.

The PCM calculates how much air enters the engine in grams/second. Than slash that to the commanded AFR and find the needed fuel in grams/second.

The grams of fuel needed are converted to inj pulse width with the help of engine rpm and fuel flow constant.

So you need a dead spot fuel flow constant. It should be 43.5psi /3 bar at WOT, if it is other than that check your regulator or gauge.

Than the PCM adjust the voltage offset. At lower voltage the injector don`t open fast enough and the pcm compensate for the less fuel flow by adding some ms to already calculated inj pulse width.

Unfortunatelly the fuel flow of the injectors is not linear from zero. It gets linear after about 3-4ms range. Below that range they flow less in most cases and the PCM compensate by adding more ms to inj pulse width. The curve here is what matters most.

If any of this components are not accurate you will get all kind of weird conditions running lean and rich at the same time under different engine loads that require the same pulse width.

Tuning at this point is not possible.

Tuning air tables through injector constants is really bad idea that should be avoided on all costs.

Ve table should be smooth and linear accross the table. The ve value is interpolated almost anytime between 4 adjacent cells and you can jump from lean to rich really easy if the transition is not smooth enough. Maf is much easier to tune so you can give it a try. You should always tune VE and MAF at open loop until you match the commanded and the actual afr.

At this point I can only suggest to start from scratch and do it all over again the right way. Tune everything in open loop and than switch to closed loop.



On the right side I saw 02s drop to zero on several occasions with no apparant reason, suggesting bad injector.
Don`t focus that much on inj pulse width, 02s give better idea what`s happening.

I hope you can duplicate that inj difference at start up. In open loop the two sides must have almost identical readings. Some fluctuations are possible due to the data stream updates at different times accross banks.

[Terminal_Crazy]

On the right side I saw 02s drop to zero on several occasions with no apparant reason, suggesting bad injector.
Don`t focus that much on inj pulse width, 02s give better idea what`s happening.

I hope you can duplicate that inj difference at start up. In open loop the two sides must have almost identical readings. Some fluctuations are possible due to the data stream updates at different times accross banks.

I need to sort out this weird issue first.
I hadn't seen the InjPW go to zero but when they match up they are much less stable than the lhs in the offset display.
This seems to have started about 12 DEC and when I started playing with the EOIT so i'll try an earlier bin again that was ok.

It's in about 7 of the last 14 logs. I need to adjust EEhack graph so it displays the PW taller

Strange thing is, the car sounds and runs ok.

Thanks for the input.
Mitch