How important is the injector offset adder? Not the voltage offset but the injector offset adder
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How important is the injector offset adder? Not the voltage offset but the injector offset adder
Increasingly as your injector PW goes lower to where it starts affecting the fueling
Really depends on how low your Injector PW Goes...
If you've gor a big set of injectors, the PW is relatively shorter so the amount of misfueling starts to incxrease.
Anything above 1.5mS - 2mS idling is probably tuneable around
I have had injectors that didn't open reliablby below 1.5mS (actually rated at 2mS) which possibly caused issues.
Mitch
Any fool can go in and set the flow rate and the motor will run fine above 20% throttle. But if you want idle and part-throttle drivability, and especially if you want it to start quickly and smoothly, you have to have the short pulse adders and voltage offsets correct, respectively.
The way Ford labels and characterizes their injectors is really helpful - they actually have a number called MINPW which is the minimum pulsewidth the injectors will reliably fire. The last time I sized injectors for a friend's build, we were looking hard at injectors that had this data available. For this particular situation we actually discovered that a set of 80lb injectors had a lower MINPW than the 60lb injectors he was considering, even though the 60s would have met the fuel needs of the motor. Given that this was a heavy manual transmission car, I insisted that the injectors be able to reliably fuel down to 400rpm during clutch engagement, and so the 80s would have been the better choice despite their higher peak flow.
Ford also includes two slope values (a high slope and a low slope) and a transition point. This transition point is where the pulsewidth gets so short that the magnetic field delays and the pintle rise/fall times become significant relative to the requested pulsewidth. Here's an example. https://performanceparts.ford.com/pa...-9593-lu34.pdf It's at this transition point where the GM short pulse adders start to grow. There are some posts out there how to convert the elegant Ford values to the verbose GM values, but the result is perfectly characterized injectors from the first crank.
Personally I'm running 2011-2017 Ford Mustang GT injectors in my LT1 with fabulous drivability.
It continues to blow my mind how places like Racetronix advertise GM injectors with NONE of these critical parameters available. Maybe they have it on their forums, but their rules state you have to buy something before they'll give you forum access. Huh?
I'll add too - when I swapped to Bosch D III injectors , just 32 lbs, I found that I had to just zero out the pulsewidth adder (not batt. voltage offset), because the Bosch injectors are the other way. I was told they flow more fuel at low PW, and with LT1 you can't take away only add, which is the wrong way. So it depends on which injectors you use as to what all you change in the tune. FIC was absolutely no help on this, even though I bought the injectors through them. They had the data somewhat tailored for the LS1 crowd.
I'm running fic blue demon 36lb injectors had same issue fic was no help. Issue I'd been having was cruise drivability bucking and the afr bouncing a lot. granted I have a pretty big cam. But idle and fire up have been no issue. I'm running sd because I was having issues with maf tuning with my 110 LSA but I've got it pretty close now in sd without changing my adder thanks to trimalyzer. Still think there's more room for improvement there though. But what you're saying is you zeroed yours out? Think I should go back to my base tune zero them out and start over?
Also thank you to everyone for your replies. A lot of helpful information
Why not give it a shot, and if it doesn't work, go back to what you had.
I don't have experience with this issue, but what came to mind was this thread on here where they delayed the injector start time until after the exhaust valve closed to avoid putting raw fuel into the exhaust. Have you tried that to see if it cleaned up the AFR instability when running in MAF mode?
I have not tried that no. Not sure how I'd go about that on a 95 lt1 but I've had pretty good success switching over to sd in terms of drivability, after much tuning obviously. I am running a wideband as well as my factory o2s and they're reading pretty close so I don't know that raw fuel tainting was so much the issue as much as what happens to readings from the maf with big cams. I also don't have as much experience in tuning maf as I do sd but It was a terrible tune, worst mail order I've ever seen. I might mess with it more in the spring or when weather permits but it's started snowing here already
I ran across this thread a week or so back when I "forked" an EOIT thread to hopefully spark more focused and meaningful discussion on that particular subject.
Anyway, the more I read the more I find in common. I'm also running a set of "recapped" / redrilled inectors from FIC. I asked them for data ahead of the purchase and was promised something would be shipped with the injectors but found no such information included in the shipment and received no further responses from them on the subject. These were sold as 42lb/hr bosch IIIs. Upon opening the package I found a set of 8 GM 12561462 / Bosch 0280155931 grey injectors that likely began life as 28 lb/hr LS1 injectors.
Back to the present - several hours of reading later (most important reading found here) I come to a fuller realization that the original injector data is likely all but useless.
So I'm wondering if anyone has any ideas / recommendations on who might be able to properly flow test injectors. Not an injector cleaning shop type test, but a real characterization test that demonstrates slope and offset at different pressures and voltages.
I'm discovering that the slow and painful way. Though I've achieved relatively decent results using the SVO injector offset vs. voltage table, I think more accurate injector data couldn't hurt. After "a lot" of reading on the subject I've come to find that anyone that tests injectors and specs static flow rate should probably not be trusted to provide a truly matched set of injectors. And by matched I mean injectors that share the same flow characteristics at all pulsewidths, pressures and voltages. I believe this is why this particular company generally removes the Bosch part number from the body, and sometimes paints their "matched" injector sets (blue, hence the name "blue demon").
Would you have a part # on those?
BR3E-EB-B556V is what I just pulled off the bodies of a set on eBay. I'm not near the car at the moment. Just make sure not to get the 18-19 ones as they're much smaller flow since Ford went to a combo direct AND port injection setup in 2018.
Similar experience with FIC. They don’t seem to understand the importance of this data for proper tuning. I will never purchse from them again.
There is a company near me called deatschwerks, they do all types of stuff with pumps, injectors etc.
One of the services they offer is offset testing. I have used them before with positive results
I'll add a me too to this list
I'm now on my 5th set.
30# venom off ebay seemed ok at the time before I rebuilt the engine.
Since the rebuild I've had a low speed surge I could never get rid off.
Injectors have been swapped bank to bank & end to end with no changes.
suspected injector data as tune had them zeroed out... makes sense if you don't know what they are.
From FIC (Fuel Injection Connection)
30lb Modified Bosch 3 Injectors ( Stainless later core )
No data. still ran the same. excellent other than low speed idle.
42lb @ 3 Bar Modified Bosch Blue Demon 3 Fuel Injectors
No data again still ran the same. excellent other than low speed idle.
Managed to get "some" data that didn't make much sense.
Bought some "Black Ops" off the net. read reviews etc.
Got "some data". Data on sheet doesn't match spec's quite the same & some variance on spray numbers etc.
No real change to the way it ran.
Given up with Black Ops injectors dropping out at low injector Pw..
Min Listed PW is 1.4mS & I'm running idle around 1-1.2 other than that they are OK once rolling.
Bit the bullet and went for "recommended" "quality" injectors from the _other_ FIC (Fuel Injector Clinic)
445cc (50 lbs/hr at OE 58 PSI fuel pressure) FIC Fuel Injector Clinic Injector Set for LT1, LT4 engines (High-Z) (IS300-0445H)
again got data ( off their website). Again didn't quite match the specs on the sheet. again some variance on the flow (They could write anything on the sheet though)
Had to write a program to calc data required. Also flow rate is now a lot lower than it was with the Black Ops.
OK My issue is still there but AFR is a little more stable than it was and is more readable on the guage. ( after trimming the AFR range etc)
I've just raised the low pulse adder and it has richened up the idle quite a bit. ( I just slid the slope along a few points).
Idle is in the 1.7mS time now rather than 1-1.2 with the black Ops so small pulses aren't dumping as much fuel.
Injector EoIT is currently at &63.
Car ran pretty well yesterday on a short run out.
it was generally rich (as i'd raised the low pw adder)
Sounds much smoother, not as lumpy.
seemed to cruise much better when lifting and turning corners.
We'll see once it's dialed in a little better.
I don't think the numbers really matter if the injectors are within running spec. They can be tuned generally to run OK
NON of the five sets (or the stock ones) actually flow anywhere near the "correct flow rate"
That's just a starting point with the voltage figures they all supply.
Get it running close with that then adjust VE tables A LOT.
Then when VE hits 100+ ADJUST & REPEAT A LOT.
When it's lean around the idle and below, try raising the low pw adders if they are around that figure.
If they are rich at idle, lower something else and try adding in some slope to the low pw adders.
That was just going to be a "me too" post.
Mitch
This is why Injector Dynamics can get away with charging astronomical prices for injectors. As that PDF indicates, they know what they're doing and how to properly characterize injectors so tuners have a known starting point. What drives me crazy is you KNOW the OEMs need and have that data, and yet the aftermarket is often fumbling around in the dark whenever you ask for anything beyond flow rate. Those mustang injectors I mentioned are $300 a set from Ford racing and you can find them much cheaper used, and the characterization data is in the PDF I posted above. Anyway, rant off. This is why I stick with only injectors with available data, whether from a GM tune file or Ford racing data sheet or similar.
Mitch I'm beginning to think a lot of your difficulties are related to low pulsewidth mismatch and / or inconsistency.
My suggestion to you would be to go here and read everything.
Then go here and read everything.
I contacted Greg Banish last night to see if he would be willing to do full flow testing and he suggested it's not worth the expense and that I look for a set of LS3 / LS7 injectors and run them at 4 bar.
I'd like to give FIC the benefit of the doubt because as I've mentioned I'm not horribly disappointed with the low flow fueling with these current injectors. But I'm relatively sure we'd all be time + money ahead to leave modified injectors alone unless all we're interested in is accurate PE fueling.
Thanks! Those look to be a drop-in except for the connectors. The only thing I dislike about using the Bosch injectors in place of the fat body Multecs on the LT intake is the need for something to stop them from "falling out" of the fuel rail. On my current injectors I cut stainless lock washers and fit them into the groove above the lower o-ring, but these look like the shoulders are large enough to act as stops.
Edit: nevermind, I just found your other post on these here (datasheet also). I guess that'll give me an excuse to turn some spacers for them on the lathe.
Hi Scott
After reading your post and a couple of threads, i looked back at few logs.
I don't think it's the injectors.
It's only since I moved the EoIT from &60 to &63
The last 4 or five logs have some really weird shit happening.
fic_12b16 is a warm up into CL
http://www.sand-hill.uk/Terminal_Cra...c_12b16.eedata
http://www.sand-hill.uk/Terminal_Cra.../fic_12b16/jpg
fic_13a1 is the last run I mentioned in the other post that ran ok ??
http://www.sand-hill.uk/Terminal_Cra...ic_13a1.eedata
http://www.sand-hill.uk/Terminal_Cra...g/fic_13a1/jpg
On the warmup log, I've mentioned before about the RHS injector dropping out at about 56-60C
On the drive log, the two Injector PW are all over trhe place. NOT seen that before.
I've always watched the O2's until it warmed up and went CL.
I presumed it was the O2's heating up
I've never really watched the Injector PW.
I'll have to try my stock base tune again.
Yes O2's were both replaced again not long ago.
Mitch
Yeah, as long as you don't start a run on these injectors on eBay. I need one more set for a car I recently acquired and am grousing about having to pay $90 shipped for a set when Rousch was selling new takeoffs with 3 miles on them a few years back for $49 shipped.
Wow those injector pulsewidths are wacky! Almost looks like one of the data streams is getting smoothed or something. The cold start one is really wacky. If you have dual exhaust, do the tailpipes smell different?
Are your individual cylinder trims all set to 1 or have you tweaked them?
All I'm saying is you seem to be continuously chasing ghosts and the modded injectors seem like they might be the common thread.
Sounds like the run is already on. $90 for 8 sounded like a good deal to me so I grabbed a set this morning that had that part # specified in the main / short description. But in the seller description after the seller specified they came off a 2016, the part # they give seems to be the 2018-19 small injector (JR3E-9F593-AB). So I'm already off on the wrong foot.
Just done a warmup with a base log.
http://www.sand-hill.uk/Terminal_Cra...une-Warmup.jpg
http://www.sand-hill.uk/Terminal_Cra...-Warmup.eedata
I altered the bare minimum
12B4C * Injector Flow Rate changed from 24.912 lbs/HR
129D5 * Injector Voltage Offsets changed.
129F5 Injector Offset Adder changed.
129F5 Injector Offset Adder changed.
126d5 Min Injector Pulse changed from 1.40 BPW (0x005C)
126d7 use this value when MIN inj pulse reached changed
12B4E Cylinder Volume changed from 717.25 ml/Cyl
12BEE * VE Table - Primary (400-2000RPM) changed.
12C8A * VE Table - Extended (2000-7000RPM) changed.
Forgot to switch off the MAF
EGR,EAS (AIR pump) AND 1-4 control DTC's Not switched off.
Sounded much louder & rougher idle but only 800rpm
It went CL when Splits 121-133 appeared so of course PW don't match.
Questions
Why do Inj PW start off different in those earlier logs?
I thought OL didn't use the O2's
BLM's under 128 are not remembered
The 2 scalars
126d5 Min Injector Pulse changed from 1.40 BPW (0x005C)
126d7 use this value when MIN inj pulse reached changed
I had them sat at 0.79 which is where these injectors should operate (min Inj switching)
Is this too low ???
This is idling around 2ms. I was around 1.65.
Lowest PW went down to about 1.0...
IF I set it around 1.00 it shouldn't go lower than that and go any leaner than what 1.00 would inject.
ie IF PCM requests 0.8 mS we still get 1.00 worth of fuel ?
Inj Offset Adder table tually starts adding fuel at 1.220 mS now
PCM hardly ever went below 1.00mS as AFAIR even with the Black Ops in.
Mitch
I'm sure that's the right part number. I've been watching several of those auctions and the 2018-2019 ones have a white clip around the upper ends of them. Immediately contact the seller if there's any confusion. eBay gives buyers an hour to back out for any reason and you can also cancel if the item is not as advertised.
No. I've measured the difference in AFR by dropping each cylinder & scaling off one of the centre results.
I'm out of ideas.
These are from Fuel Injector Clinic -http://fuelinjectorclinic.com/ls1-ls6/IS301-0445H
... These injectors utilize the latest technology and provide great linearity and short pulse width repeatability.
After several sets, I'm fairly comfident it's not the injectors.
Don't you just love this hobby :-)
Mtch
I run in the same issue with 98 ls1 injectors, the remedy was to add a second o-ring in the upper slot. Worked really well.
I resolved the injector problems long time ago. Just grab yourself a good GM ls injectors and read this thread
http://www.gearhead-efi.com/Fuel-Inj...njector-tables
I even have an updated version that reads injector voltage for ultra precision.
When I switched over from a crap Accel to stock 98 ls1 all of the surging has gone. So definitely crap injectors do cause surging.
Another thing that I noticed shortly before the crap Accel died completely. When cold they run fine only to turn to crap when warmed up. The AFR was jumping all around with no reason and the engine was untunable.
It is. I asked the seller to cancel and hope that's the last I hear of it. The seller is clear in the short and long description that they're off a 2016 5.0, but if you zoom in on the second image you can faintly make out JR3E-9F593-AB. That's the smaller 2018 and up injector right?
These can be bought new from a particular large volume retailer for $33 each. That's actually not bad for a new piece. A far cry from $50 for a set of 8 but still...
Mitch is it possible you've got the wrong injector data? Those don't look to be modified injectors so maybe they aren't. You mention the offset adder coming in at 1220 us now. I haven't pulled the specs off their site yet but that seems odd. Most of these newer injectors flow higher in the low pulsewidth slope, which the $EE mask doesn't support so everyone just zeros it out. However, I've never seen mine idle below 1.4ms while it was a 355 / 5.7l.
This is what I did with my Bosch D3s and it worked well also. I found out from experience the o-rings can slip if you get in a hurry to slap the fuel rails back in and the pressure side isn't seated fully. These are pretty sturdy and there's less chance of fuel spraying everywhere.
Attachment 13574
I've seen your LS table mods and that's very cool. My concern in this thread is geared more towards modded injectors and inaccurate characterization data.
No Idea.
The Web page publishes data for them.
Data sheet in the box is slighty different.
And the "Flow matched set aren't all the same value on the sheet. SN on injectors don't match sheet.
Seems to be the norm.
42lb
42.5lb@3bar
44.1 @ 47.psi
Flow rate is now currently set at 38.511 with VE's to match as it was very lean.
I'd HOPE a company publishes correct info but who knows.
I got "data" for the slope.
I had to write software to Interpolate it to get it to fit our tables, the same as the Voltage offsets and fuel pressure vs flow rate.
I had "slid" the table along to add more fuel down low for the last few runs.
That worked somewhat for the Black Ops injectors.
I read on Tuner groups where you dial in 14.7 AFR and that's it.
I feel this is trying to balance on the head of a pin.
Keep going fatter with no change until suddenly it's pig rich 12-13 but nice and stable
or
lean it back a bit & it's 15-17 AFR and erratic.
Mitch
Does anyone know what the following tables do?
2692 IAC Adder - AC pressure -
OK That one seems obvious.
I was going to zero it out as the AFR guage is on the AC.... Don't want it opening IAC when we go lean right?
20CD ac Low Pressure charge vs table -
What does it do ?
WAS all 255 - Do I zero this out?
20DA ac low charge vs table - and this ?
20E7 ac low charge vs table - and this ?
TIA
Mitch
These look like a particularly good fit also. Do you know of any reason to shy away from buying the Bosch branded part versus one in Motorcraft packaging? The Bosch branded ones seem to be significantly less expensive.
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.
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.
I'm a big fan of science. Not such a big fan of hope.
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.
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.
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.
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.
Hi Scott,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.
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.
Again, that's presumingQuote:
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.
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 ?
Agreed & see above.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.
I'd be interested to see what you come up with just for comparisonQuote:
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.
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
Aha, I hadn't thought of that. Excellent.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.
Thanks
Mitch
(Think I'll go back to bed, it's half three in the morning. )
I also hijacked this thread, but honestly I think your issue may not be too off topic.
Do you mean another PCM?
Have you double checked all your PCM grounds?
I did look briefly at the data FIC(linic) had for the 445cc injectors. That's what you're running currently, right? Anyway, it was all but meaningless to me b/c all the tables were expanded to use MAP. I'm interested in how you interpolated the data for the $EE tables. I know dzidaV8 has some excel stuff floating around but I'd prefer not to have to use M$ Excel if possible.
No offense but that seems like backwards thinking. If you have injectors that were supposed to be 42 lb/hr and they're running leaner than another set (assuming your VE stayed the same) there are three primary things that could be wrong. Those are IFC / high slope, low pulse adders / low slope, and offset.
It does sound like you may have other weirdness going on there, as well as a lot of other variables. I didn't know your MAF had been messed with. You mentioned that you forgot to turn off the MAF in your initial "back to starting point" tune earlier. I trust you fixed that and you're still getting the odd behavior with PWs all over the place?
Do you still have your factory Multecs? I'm seriously debating putting mine back in for first fire.
I noticed you are using some beta version 4.8 of eehack.Quote:
The 1st shows a really BIG difference in the injector PW on cold startup. about 2mS & 6mS initially.
Where did you get it. Last stable release was 4.7 , and I used 4.7 as a base for all mods I have done.
It could be that this beta version has some bugs in the datastream.
I suggest you to switch to 4.7 or the one I modified and try to duplicate that condition. It is weird because narrowband 02s are the same accross the banks and did not get lean, on the right side with that much fuel you should get a stall at cold start up.
I suspect a bad injector on the right side also, you got intermitten lean conditions on the right side which resembles me the same conditions I got with an injector set that went in the trash bin.
That random errors also suggest a bad wiring or bad pcm. You should check for melted wires around headers.
On another note, Why don`t you get a 85mm truck MAF and give it a try. It is not that expensive and will support a lot more airflow. Delphi units goes for 70-80$.
HI
Yes, I don't have a spare atm.Quote:
Do you mean another PCM?
The only other thread I've read about surging not going away, the poster changed their cam.
Not yet but after cleaning/reseating the injectors I'll check all grounds & PCM connections as well.Quote:
Have you double checked all your PCM grounds?
The Online Data doesn't mach up with the supplied data[/QUOTE]Quote:
all the tables were expanded to use MAP. I'm interested in how you interpolated the data for the $EE tables.
I originally emailed FIClinic:
Which kPa value i would use for an LT1 with the 16188051
OBD1 PCM for the Voltage offsets.
The fuel system is the std 3 bar with the referenced FPR. So I'm thinking I
would use 300kPa vaules from the table
Response was: 300kpa values should work fine.
Data supplied: I'll scan data sheet if anyone is interested.
Slope flow matching data: Average flow rate at 43.5psi = 428cc/min. Your set is Flow matched within 1.9%
Injector offset matching data: Average offset at 3bar & 13.5V 962uS. You set is matched within 1.4%
In my notes Fuel pressure at Idle with Vac hose off is 47psi (which is what the engine should see under WOT)
**** So we need to use the 47psi injector kPa value ===
1 psi = 6.89476 kPa
47 psi = 324.05372 kPa
LS table Spacing is spaced 16.0kPa which is approx 2.3206038037 psi
I don't use MS Excell but I do use Libre Office Calc and none that I have are able to Interpolate data...
So I wrote a program to do a linear interpolation (don't ask about slope matching) to generate some nos.
This gives Interpolated results of
Volts Kpa From Next table
0.000000 324.050000
========================
0.400000 291.645000
0.800000 259.240000
1.200000 226.835000
1.600000 194.430000
2.000000 162.025000
2.400000 129.620000
2.800000 97.215000
3.200000 64.810000
3.600000 32.405000
4.000000 0.000000
4.100000 0.000000
4.200000 0.000000
4.300000 0.000000
4.400000 0.000000
4.500000 0.000000
4.600000 0.000000
4.700000 0.000000
4.800000 0.000000
4.900000 0.000000
5.000000 0.000000
5.100000 0.164857
5.200000 0.329714
5.300000 0.494571
5.400000 0.659428
5.500000 0.824285
5.600000 0.989142
5.700000 1.153999
5.800000 1.318856
5.900000 1.483713
6.000000 1.648570
6.100000 1.643023
6.200000 1.637475
6.300000 1.631928
6.400000 1.626380
6.500000 1.620833
6.600000 1.615285
6.700000 1.609738
6.800000 1.604190
6.900000 1.598643
7.000000 1.593095
7.100000 1.584205
7.200000 1.575315
7.300000 1.566424
7.400000 1.557534
7.500000 1.548644
7.600000 1.539754
7.700000 1.530863
7.800000 1.521973
7.900000 1.513083
8.000000 1.504192 2.100000
8.100000 1.492807
8.200000 1.481421
8.300000 1.470035
8.400000 1.458649 1.967172
8.500000 1.447263
8.600000 1.435877
8.700000 1.424491
8.800000 1.413106 1.834345
8.900000 1.401720
9.000000 1.390334
9.100000 1.377277
9.200000 1.364220 1.701517
9.300000 1.351163
9.400000 1.338107
9.500000 1.325050
9.600000 1.311993 1.568690
9.700000 1.298936
9.800000 1.285880
9.900000 1.272823
10.000000 1.259766 1.435862
10.100000 1.245878
10.200000 1.231990
10.300000 1.218102
10.400000 1.204214 1.363448
10.500000 1.190326
10.600000 1.176438
10.700000 1.162550
10.800000 1.148662 1.291034
10.900000 1.134774
11.000000 1.120887
11.100000 1.106987
11.200000 1.093088 1.218621
11.300000 1.079189
11.400000 1.065289
11.500000 1.051390
11.600000 1.037490 1.146207
11.700000 1.023591
11.800000 1.009692
11.900000 0.995792
12.000000 0.981893 1.073793
12.100000 0.968827
12.200000 0.955761
12.300000 0.942695
12.400000 0.929629 1.024345
12.500000 0.916563
12.600000 0.903497
12.700000 0.890431
12.800000 0.877365 0.974897
12.900000 0.864299
13.000000 0.851232
13.100000 0.839822
13.200000 0.828411 0.925448
13.300000 0.817001
13.400000 0.805590
13.500000 0.794180
13.600000 0.782769 0.876000
13.700000 0.771359
13.800000 0.759948
13.900000 0.748538
14.000000 0.737127 0.826552
14.100000 0.728220
14.200000 0.719312
14.300000 0.710404
14.400000 0.701496 0.793103
14.500000 0.692588
14.600000 0.683680
14.700000 0.674773
14.800000 0.665865 0.759655
14.900000 0.656957
15.000000 0.648049 0.742931
15.100000 0.642464
15.200000 0.636878
15.300000 0.631293
15.400000 0.625708
15.500000 0.620123
15.600000 0.614537
15.700000 0.608952
15.800000 0.603367
15.900000 0.597781
16.000000 0.592196 0.659310
16.100000 0.590775
16.200000 0.589355
16.300000 0.587934
16.400000 0.586513
16.500000 0.585093
16.600000 0.583672
16.700000 0.582252
16.800000 0.580831
16.900000 0.579410
17.000000 0.577990
17.100000 0.577990
17.200000 0.577990
17.300000 0.577990
17.400000 0.577990
17.500000 0.577990
17.600000 0.577990
17.700000 0.577990
17.800000 0.577990
17.900000 0.577990
18.000000 0.577990
18.100000 0.577990
18.200000 0.577990
18.300000 0.577990
18.400000 0.577990
18.500000 0.577990
18.600000 0.577990
18.700000 0.577990
18.800000 0.577990
18.900000 0.577990
19.000000 0.577990
19.100000 0.577990
19.200000 0.577990
19.300000 0.577990
19.400000 0.577990
19.500000 0.577990
19.600000 0.577990
19.700000 0.577990
19.800000 0.577990
19.900000 0.577990
20.000000 0.577990
Figures supplied & Interpolated were
Volts PSI
0.000000 47.000000
=================================
0.400000 44.755000
0.800000 42.510000
1.200000 40.265000
1.600000 38.020000
2.000000 35.775000
2.400000 33.530000
2.800000 31.285000
3.200000 29.040000
3.600000 26.795000
4.000000 24.550000
4.400000 22.305000
4.800000 20.060000
5.200000 17.815000
5.600000 15.570000
6.000000 13.325000
6.400000 11.080000
6.800000 8.835000
7.200000 6.590000
7.600000 4.345000
8.000000 2.100000
8.100000 2.066793
8.200000 2.033586
8.300000 2.000379
8.400000 1.967172
8.500000 1.933966
8.600000 1.900759
8.700000 1.867552
8.800000 1.834345
8.900000 1.801138
9.000000 1.767931
9.100000 1.734724
9.200000 1.701517
9.300000 1.668310
9.400000 1.635103
9.500000 1.601897
9.600000 1.568690
9.700000 1.535483
9.800000 1.502276
9.900000 1.469069
10.000000 1.435862
10.100000 1.417759
10.200000 1.399655
10.300000 1.381552
10.400000 1.363448
10.500000 1.345345
10.600000 1.327241
10.700000 1.309138
10.800000 1.291034
10.900000 1.272931
11.000000 1.254828
11.100000 1.236724
11.200000 1.218621
11.300000 1.200517
11.400000 1.182414
11.500000 1.164310
11.600000 1.146207
11.700000 1.128103
11.800000 1.110000
11.900000 1.091897
12.000000 1.073793
12.100000 1.061431
12.200000 1.049069
12.300000 1.036707
12.400000 1.024345
12.500000 1.011983
12.600000 0.999621
12.700000 0.987259
12.800000 0.974897
12.900000 0.962534
13.000000 0.950172
13.100000 0.937810
13.200000 0.925448
13.300000 0.913086
13.400000 0.900724
13.500000 0.888362
13.600000 0.876000
13.700000 0.863638
13.800000 0.851276
13.900000 0.838914
14.000000 0.826552
14.100000 0.818190
14.200000 0.809828
14.300000 0.801466
14.400000 0.793103
14.500000 0.784741
14.600000 0.776379
14.700000 0.768017
14.800000 0.759655
14.900000 0.751293
15.000000 0.742931
15.100000 0.734569
15.200000 0.726207
15.300000 0.717845
15.400000 0.709483
15.500000 0.701121
15.600000 0.692759
15.700000 0.684397
15.800000 0.676034
15.900000 0.667672
16.000000 0.659310
Accurate choice of two there !
FIC Inj Short Pulse adder
Mix of two PCM tables
Inj Pulse adder
0.0 0.250 0.0 0.250
0.06 0.236
0.1 0.227
0.12 0.222
0.18 0.209
0.24 0.195
0.30 0.181 0.3 0.182
0.36 0.167
0.4 0.159
0.43 0.153
0.49 0.139
0.5 0.136
0.55 0.126
0.6 0.114
0.61 0.112
0.67 0.098
0.73 0.084
0.79 0.029
0.8 0.068
0.85 0.057
0.9 0.045
0.91 0.043
0.97 0.029
1.0 0.023
1.03 0.015
1.09 0.001
1.1 0.0
1.16 0.0
Interpolated data (LT1 table min division is 15.3uS)
====================
488=139.2 == 137.2 0x09
549=126.2 == 122.1 0x08
610=112.0 == 106.8 0x07
671= 97.5 == 91.6 0x06
732= 81.2 == 76.3 0x05 *
793= 69.3 == 76.3 0x05 *
854= 56.0 == 61.0 0x04
915= 41.6 == 45.8 0x03
976= 27.6 == 30.5 0x02
1037= 13.1 == 15.3 0x01
1098= 1.0 == 0.0 0x00
The 4.8 I think was from Steveo's site. This is on the PC in my office. The car is either running 4.7 or your 13_10_2018_v2 version.Quote:
The 1st shows a really BIG difference in the injector PW on cold startup. about 2mS & 6mS initially. I noticed you are using some beta version 4.8 of eehack.
Where did you get it. Last stable release was 4.7 , and I used 4.7 as a base for all mods I have done.
It could be that this beta version has some bugs in the datastream.
I suggest you to switch to 4.7 or the one I modified and try to duplicate that condition. It is weird because narrowband 02s are the same accross the banks and did not get lean, on the right side with that much fuel you should get a stall at cold start up.
If you look again, in the 2nd jpg, both injectors are around 5 or 6mS.Quote:
I suspect a bad injector on the right side also, you got intermitten lean conditions on the right side which resembles me the same conditions I got with an injector set that went in the trash bin.
That random errors also suggest a bad wiring or bad pcm. You should check for melted wires around headers.
This is on a bog stock Z28 tune.
The fault seemed to be on the LHS
A new PCM is on its way.
What I find strange is that
a: the O2's don't suggest anything odd but then they are still cold.
b: How or WHY is the Injector pulse calculated differently for each bank ?
I replugged/sprayed cleaner on the injector connectors between runs.
I never got that far with the tuning :-)Quote:
On another note, Why don`t you get a 85mm truck MAF and give it a try. It is not that expensive and will support a lot more airflow. Delphi units goes for 70-80$.
I started tuning SD and this lean surge has never fully gone away unless I dump fuel into it.
Mitch
The fact that they gave you a specific offset and static slope is promising.
Unless you have an adjustable FPR I think I'd regenerate your data using 43.5 / 300kpa unless you have an overwhelming amount of faith in the accuracy of the gauge that 47psi was measured with. If it's a typical shop grade gauge that registers 0-100, a 3-5 psi indicator error along with a 3-5% linearity error is not unheard of. Here in the states we have the "miracle" of Harbor Freight which is a huge importer for extremely low grade instruments such as the one I purchased. Mine would read 46 psi on my 4 bar vehicles. Most troubleshooting guides will tell you a 4 bar system won't even start at 46 psi. I replaced the original junk gauge with a $20 liquid filled gauge from the hardware store and it reads in the relative neighborhood. But I still wouldn't use it as a calibration reference.
I was more interested in the method you used for interpolation than the data. I'd really like to develop something that works in libreoffice. But that would probably be info better suited for a different thread.
Good luck...
Edit: Another simple check I would suggest is measuring your injector impedances from the PCM connector while having a helper jostle the harness around. This would tell you if all the injector leads in your harness are intact.
Hiya
Quick update. I still have some weird shit going on...
OK I've spent the afternoon recalculating the Offsets
I recalculated IFC at 44.1 (47psi) which should be very lean from 38.51 (about 14%))
I see what you save above, so can still pull it back to 42 later.
I used the data of the website to recalc the Voltage Offsets.
At 13.6V the difference is about 11.5% lower
Reset the Low PW adder table
I Flashed with Kur4o's 13_10_2018 EEHack 4.90
I Have NOT altered the in car laptop to view the InjectorPW so didn't see the same issue as befor until I got the log up on my desktop.
First start, by 86C had idle BLM's at 138 154 - not too shabby
as it got hotter BLM's moved.
141 154
143 154
144 154
146 147
148 148 OK
went for short drive RH BLM 16 topped out at 160
Trimalyzed data which really increased the low map areas up & went out again.
Car ran OK and was generally happy
Surge was still present but car did idle at 7mph quite happily.
Surge came on as soon as increased throttle 1.2% and went off after about 15mph (8%tps)
I might pick up some O2 sensors and replace them as well as checking all the grounds and cables etc.
I still don't KNOW why the InjPW would be different in Open Loop ?
Interpolation of data:
I don't use MS Excel and my use of LibreOfficeCalc is limited
I don't think interpolation is available as std. There seemed to be some extension available for Excel.
The maths to fit curved data was well outside my field.
I started to read an glazed over.
So my program just uses linear interpolation.
For day to day use I have ARM processor based computers as well as PC's and Linux boxes.
My main computer runs RISCOS, written by Acorn from the original BBC micro back in the 80's who then went on to develop the ARM processor.
For quick calculations I either use BBC Basic an easy & fast programming language or write programs in C/C++
Anyways. for the interpolation, I take a data table such as
0 5
10 100
decide how many points I want (say 5 across the columns and 5 between the rows )
Precalculate the size of grid needed to fit the data in so i end up with
0 x x x x 5
x x x x x x
x x x x x x
x x x x x x
x x x x x x
10 x x x x 100
Then move across the cells. Dividing the difference up as a fraction of the difference (5-0 =5. 5/5==1 ) so we get 0+1x1, 0+2x1, 0+3x1, 0+4x1, until we hit the next row
I then calculate the next data row 10 to 100 so that is (100-10=90. 90/5 == 18 ) so we get 10+1x18, 10+2x18, 10+3x18, 10+4x18
this gives me
0.000000 1.000000 2.000000 3.000000 4.000000 5.000000
x x x x x x
x x x x x x
x x x x x x
x x x x x x
10.000000 28.000000 46.000000 64.000000 82.000000 100.00000
Then traverse the grid for each column which gives us
0.000000 1.000000 2.000000 3.000000 4.000000 5.000000
2.000000 6.400000 10.800000 15.200000 19.600000 24.000000
4.000000 11.800000 19.600000 27.400000 35.200000 43.000000
6.000000 17.200000 28.400000 39.600000 50.800000 62.000000
8.000000 22.600000 37.200000 51.800000 66.400000 81.000000
10.000000 28.000000 46.000000 64.000000 82.000000 100.000000
IF you can explain how to calculate this any better to fit curved tables i'd be interested.
As it is, each grid virtex (4 points) are plotted linearly onto a plane.
Mitch
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.
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
That was measured fuel pressure.
I recalculated the voltage offsets with the online generic data rather than off the supplied sheet.
Change from previous data was about 10-14% lower. IFR raised back to rated 42# an increase of about 14%
I then recalculated offsets back at the 300kpa pressure and there were minor differences.
Reflashed with EEHack 4.7
Initial fire up was a bit rich, blm’s sat about 151-121 so I resloped the VE Tables.
This change has brought the low corner of the VE table up quite a bit and doesn’t drop off like a ski slope now.
Blm sat at 126-127.
Needs a run out now.
New pcm and o2’s are on their way.
Issue withe InjPW seems to have gone so maybe just a wierd flash issue.
Mitch
I got a little confused what you are trying to do.
First you need that fuel flow figured. If you have the fuel flow at 42 pounds at 4 bar, you need to convert it to 3 bar flow.
The formula is x*0.86602540378
x= fuel flow at zero vacuum at 4 bar fuel pressure, [zero vacuum value should be the lowest value in the ls data].
Than you have to convert the voltage offset. You should have a ls data table called injector offset vs vacuum vs volts . Take again the row at zero vacuum and interpolate to lt1 voltage . It will take some time but it can be done by hand easily.
For what it's worth, on every older LT1 I've measured, the fuel pressure has always been on the high side, usually 3-4psi higher than spec.