Appologies to anyone if this thread has gone off topic or been hijacked somewhat.
I have another 2 images of the last start
http://www.sand-hill.uk/Terminal_Cra...se_start_1.jpg
http://www.sand-hill.uk/Terminal_Cra...Log/base-2.jpg
The 1st shows a really BIG difference in the injector PW on cold startup. about 2mS & 6mS initially.
IF this is SDOL (NO MAF, 11C and car not run for 24 Hrs)... WHY is the injector pulse 3 times bigger on the RHS?
Even if i unplugged 1 bank of injectors surely the PCM should'n't know or care at this point?
I did a quick unplug of the injectors and sprayed switch cleaner on all contacts & got the 2nd log
where both InjPW are very similar.
Just another quirk.
I did get another bunch of odd DTC's bounce on and off like i've mentioned before
43 & 43D - Knock sensors - OK LH bank had no fuel so I get those two.
99 Tach output circuit - switched off - still appeared.
97 VSS 4K pulses circuit fault
They have usually gone away after a brief time, maybe related to the lean issue
O2's don't show anything but they are cold. InjPW is not something I've doggedly watched previously.
I never drive until it's hit 86C anyway.
What I have realised is I'm using a socketed PCM with no known provenance so I've ordered another.
I did resocket the last one I bricked but the Prom programmer socket went tits up after I'd flashed several E side chips and I haven't gone back to it.
Quote:
Originally Posted by Terminal_Crazy View Post
Flow rate is now currently set at 38.511 with VE's to match as it was very lean.This statement is somewhat troubling, and sort of the salient point of my concern about the subject. For what you paid for those you should be able to plug a known flow # into the IFC field and be done.
I'm by no means an expert, but I think you should be aiming to have the IFC as close to actual as possible. kur4o suggested this to me a while back and it highlighted a flaw in my tuning methodology that I think you might be practicing also. Anyone with better knowledge please jump in and correct me if wrong, but... If you need more room in your VE table you should be scaling your cylinder volume constant because it's only utilized for speed density calcs. The IFC is used by both speed density and MAF calculations - MAF being a fairly cut and dried one; air mass * target afr = reqired fuel mass, then (required fuel mass / IFC) + offset = base pw.
Hi Scott,
Ok whilst I don't entirely disagree and will accept any form of discussion...but...
(Sliding the low PW adder table along was just a recent hack to help dump fuel in.
Excess fuel in the VE is pulled out by the BLM's in CL )
I am tuning Speed Density currently.
The Cylinder size is one faily accurate known value in the calculation.
IF I was _just_ changing injectors, my VE table would be "correct"
IF the Injector data was "accurate" as I read from Greg Banish etc the injectors should swap with the new data with no issues.
The way I see it, I only know the flow rate at 1 point, (OK 5 voltages and 4 pressures) but NOT the slope
These injectors are Significantly leaner at 42# then the BlackOps at 42# and we have no provision to alter the slope Other than changing the VE table.
If the VE maxes out I can change either Flow rate or Cylinder size... I know what the cylinder size is.
Quote:
Conversely, if you wanted to find your IFC without having injector data I would think you'd want to be using MAF in OL and compare your wideband to commanded AFR. However with cam overlap you'll want to avoid doing this at lower airflows because of the effect of reversion. Also, you'd still really need to have an accurate offset vs. voltage table at the very least. I don't think there's a truly objective way to find injector offset in-situ.
Again, that's presuming
your AFR guage is correct and accurate.
Your MAF table is accurate.
Since my MAF was "ported" by the previous owner I should have no idea how innacurate it could be.
Well I did actually log & calculate it years ago to correct the MAF table.
15 years on, is it still accurate ?
Quote:
Quote Originally Posted by Terminal_Crazy View Post
I had "slid" the table along to add more fuel down low for the last few runs.This is even more troubling - are you saying you were using one of the injector constant tables to try and alter fueling? That will definitely cause the ecu to do weird things. The point I've been trying to get across here is if what I'm reading is correct (and I have no reason to dispute it) the ecu needs dead accurate injector data to characterize the fluid dynamics of the injectors. Without it accurate fuel control goes out the window. Once you have accurate data, tuning should be a lot less difficult.
Agreed & see above.
Quote:
I'll try to get a look at the published specs and see what the low slope looks like for your latest injectors. It's highly possible you don't need anything in the low pulsewidth adder table and that could be causing you some grief.
I'd be interested to see what you come up with just for comparison
It goes lean. Increasing the VE is OK in OL, a fat AFR down to 13.5 ish is stable. CL just pulls it back out
Quote:
In regard to your questions on the AC pressure IAC compensators, I may also be completely wrong here but I'm relatively sure those only apply if the compressor request line is enabled. If the clutch isn't engaged the compressor can't effect engine load. But I would have to defer to someone who understands the disassembly better for confirmation of that theory.
Aha, I hadn't thought of that. Excellent.
Thanks
Mitch
(Think I'll go back to bed, it's half three in the morning. )