Blown88GT wrote:seijirou wrote:Blown88GT wrote:
All this occurred when seijirou changed from Basic Trigger (Dizzy) to Toothed wheel.
Otherwise, it's fixed at Untimed injection (greyed out) & Sequential injection is not allowed.
Read this before but just noticed the confusion which seems to be causing a misunderstanding from several readers. This isn't regarding timed / sequential injection. The problem does exist with Basic Trigger, in fact I can't test it on the bench with Toothed wheel because I don't have a jimstim, just a vanilla stimulator. I do see the problem on the car with toothed wheel configured (only a crank wheel for now, so still batch fire) and then I pulled the ECU out and hooked it up to my stimulator on the bench reconfigured for basic trigger to measure the different values between bank1 and bank2. So I am seeing the problem in both conditions toothed wheel and basic trigger.
This is an issue with Sequen
ced which the eyes can easily miss-read as sequen
tial but this is *not* a sequential problem. This is a problem with sequenced batch fire.
So...Sequenced = Injector Staging
Help Note: Sets injector staging in non-sequential modes. For Sequential set 2 Squirts/Alternating or 1 Squirt/Simultaneous.
I've always been Basic Trigger, 4 squirts/Engine Cycle & Alternating Injection Staging but would never see a difference with only one wideband.
Are you saying it should be changed to 2 Squirts?
For 8 cyl, 1 Squirt is not allowed.
Alternating effectively cuts the # of squirts per bank in half. You can have 1 squirt simultaneous, but you need 2 squirts for alternating which gives you 1 squirt per bank but not at the same time.
4 squirts per cycle alternating is 2 squirts per bank per cycle and the events are staggered bank to bank.
What's interesting about sequenced batch is that you can enable it at all with basic trigger. The tool tip mentions "same alignment with ignition event (cylinder)" but specific cylinder knowledge is not possible with basic trigger.
It is possible to know piston position on a profiled crank trigger, even if you don't know which exact cycle of the stroke you're on. If you use 1 squirt then it's useless because you still don't know if the squirt is happening on, for example, the exhaust stroke or the compression stroke both of which happen on the same ignition event so it's still random in that regard.
This is not a problem if you're going to use more than 1 squirt because there's then no distinction between the "leading" and "trailing" squirt.. you will always have one on each cycle for the same piston position. I.E. you'll get half your fuel on the compression and the other half on the exhaust stroke so it's irrelevant which of these is technically leading vs trailing.
That's all fine and dandy, but if you configure 4 squirts alternating, to give you 2 squirts per bank per cycle so that sequenced has the opportunity to actually matter then you end up with bad pulsewidth on Bank2 because there's a bug.
Without sequenced, especially on a V8, the timing of the squirts is somewhat random. Every time you start the engine it may align with the compression stroke of 1, 3, 7, or 2 (for our small block fords) which means for any one cylinder the degree of atomization vs pooling on the valve has a 75% chance of being different every time you start the engine. I should note that between these 4 cylinders even with sequenced the degree of atomization will be different between them, however whatever it is it will be fixed for that cylinder and won't change (and even though it isn't ideal, which is the job of "full sequential", consistent is still a lot better than inconsistent).
Sequenced batch is a cool idea and I'd like to take advantage of it but there appears to be 2 problems. 1. hemi discovered that with simultaneous injection and 4+ squirts the staggering has problems with regards to timing such that the separation is irregular and the distribution of pulsewidth from event event is irregular. 2. I discovered that with alternating and 4+ squirts the total pulsewidth for bank2 is being calculated incorrectly. At low commanded pw the real pw is far too high, and at high command pw the real pw is far too low.
So simultaneous 1 or 2 squirts for sequencing are the only options without bugs. 1 squirt sequenced is the same difference as 1 squirt not-sequenced as I explained above, so the only viable configuration where it could both matter and work is 2 squirts simultaneous using a profiled crank trigger.
