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Thread: 95 lt1 injector offset questions

  1. #16
    Fuel Injected! Terminal_Crazy's Avatar
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    WEIRD SHIT HAPPENING

    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
    '95 Z28 M6 -Just the odd mod.
    '80 350 A3 C3 Corvette - recent addition.

  2. #17
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    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?
    Last edited by sherlock9c1; 02-10-2019 at 05:52 AM.

  3. #18
    Fuel Injected! spfautsch's Avatar
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    Quote Originally Posted by Terminal_Crazy View Post
    On the warmup log, I've mentioned before about the RHS injector dropping out at about 56-60C
    Are your individual cylinder trims all set to 1 or have you tweaked them?

    Quote Originally Posted by Terminal_Crazy View Post
    On the drive log, the two Injector PW are all over trhe place. NOT seen that before.
    All I'm saying is you seem to be continuously chasing ghosts and the modded injectors seem like they might be the common thread.

    Quote Originally Posted by sherlock9c1 View Post
    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...
    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.

  4. #19
    Fuel Injected! Terminal_Crazy's Avatar
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    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
    '95 Z28 M6 -Just the odd mod.
    '80 350 A3 C3 Corvette - recent addition.

  5. #20
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    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.
    Last edited by sherlock9c1; 12-27-2018 at 03:11 PM.

  6. #21
    Fuel Injected! Terminal_Crazy's Avatar
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    Quote Originally Posted by spfautsch View Post
    Are your individual cylinder trims all set to 1 or have you tweaked them?
    No. I've measured the difference in AFR by dropping each cylinder & scaling off one of the centre results.

    Quote Originally Posted by spfautsch View Post
    All I'm saying is you seem to be continuously chasing ghosts and the modded injectors seem like they might be the common thread.
    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.

    Quote Originally Posted by spfautsch View Post
    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.
    Don't you just love this hobby :-)

    Mtch
    '95 Z28 M6 -Just the odd mod.
    '80 350 A3 C3 Corvette - recent addition.

  7. #22
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    Quote Originally Posted by spfautsch View Post
    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.

    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.

  8. #23
    Fuel Injected! spfautsch's Avatar
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    Quote Originally Posted by sherlock9c1 View Post
    I'm sure that's the right part number.
    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.

  9. #24
    Fuel Injected! spfautsch's Avatar
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    Quote Originally Posted by kur4o View Post
    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.
    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.

    0912181955.jpg

    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.

  10. #25
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    Quote Originally Posted by spfautsch View Post
    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.
    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
    '95 Z28 M6 -Just the odd mod.
    '80 350 A3 C3 Corvette - recent addition.

  11. #26
    Fuel Injected! Terminal_Crazy's Avatar
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    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
    '95 Z28 M6 -Just the odd mod.
    '80 350 A3 C3 Corvette - recent addition.

  12. #27
    Fuel Injected! spfautsch's Avatar
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    Quote Originally Posted by sherlock9c1 View Post
    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.
    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.

    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.

    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.

    Quote Originally Posted by Terminal_Crazy View Post
    I'd HOPE a company publishes correct info but who knows.
    I'm a big fan of science. Not such a big fan of hope.

    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'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.

  13. #28
    Fuel Injected! Terminal_Crazy's Avatar
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    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.


    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.


    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 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.

    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

    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. )
    '95 Z28 M6 -Just the odd mod.
    '80 350 A3 C3 Corvette - recent addition.

  14. #29
    Fuel Injected! spfautsch's Avatar
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    I also hijacked this thread, but honestly I think your issue may not be too off topic.

    Quote Originally Posted by Terminal_Crazy View Post
    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.
    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.

    Quote Originally Posted by Terminal_Crazy View Post
    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.
    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.

  15. #30
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    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.

    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$.

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