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Thread: lq4 swap to G-body, noob needs help refining tune

  1. #1
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    lq4 swap to G-body, noob needs help refining tune

    HI All -

    Just getting the car back together. I thought I had a blown head-gasket, but it ended up being one hell of an air pocket. Lesson learned, use a vacuum style coolant bleed / refill tool. Best money I've spent on a tool in a while.

    Ok,

    2003 LQ4 stock minus listed mods
    317 Heads
    1 7/8 Hooker Headers and 3" exhaust (no cats)
    Bullet Cam 226/234 112 LSA

    T-56 Magnum Transmission

    I've been reading a lot and download a bunch of tunes to see if I could start to see what looks right or normal. I've borrowed a spark table and a VE table from another persons tune that had a similar cam. Mostly everything else I tried to copy from a GTO file, or referenced internet wisdom.

    -Car idles well, starts well lean, then after about 30 sec - 1 minute it goes from 16 AFR to 10-11 AFR. On a warm start it's usually 15-16 AFR
    -During driving while the engine is still warming up I saw mostly 12-13 AFR (not sure if HP Tuners is logging my wide band correctly, looks to be displaying leaner than what the gauge says at times)
    - Once the engine had warmed up, the AFR dropped to near 16.00
    - During a pull my AFR read a steady 15.3

    - A problem I'm having is when I come to a light and stop, or just prior to stopping, the engine wants to die, and usually does if I don't keep my food on the accelerator pedal . My wideband goes to near 10.0 AFR, and the idle drops below my commanded 850 rpm, I noticed once it was 550ish. Is this DFCO maybe?

    All in all I'd really just like to get it closer to 13 ish AFR. Its a daily driver, would like the stop light / low speed stumble corrected somehow, and the slight surging I have if I hold a gear at low speed in the neighborhood.

    Help, guidance, or reference to more reading would be great. Thanks!

    Alex

    1 bar maf 6.0 (Monte ) v2.hptv2 monte 1st trip from cold start.hplv2 monte 2nd trip.hpl

  2. #2
    Tuner Hotwire's Avatar
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    I've got pretty close to the same setup as you do, block, heads, large long tubes, etc.

    If you're reading 15.3 aft at WOT, DON'T go WOT any longer!! That will damage your setup quick.

    I'm having the same issues w/ stalling, but mine isn't as bad as yours is.

    What I've found and am in the process of learning myself is we both need to get our MAFs tuned properly and VE tables corrected for the setup differences. Your MAF is probably in a custom intake now as opposed to the factory plastic box. That needs to be tuned. Your VE is way off due to the cam. That also needs to be tuned.

    You can get my tune from here and also see the questions/answers I'm going through *NOTICE* I'm running 33lb injectors and LS6 intake!: https://forum.hptuners.com/showthrea...iles-histogram

    I found this thread as well. I haven't had a change to put these changes into affect, but have been working on making the changes.
    http://www.silveradoss.com/forums/to...sing-hptuners/
    Last edited by Hotwire; 10-22-2018 at 07:19 AM.
    *Jeff*
    2002 4dr 2wd Blazer, 06 L33, LS6 cam, built trans, etc.. SOLD
    2008 Tahoe Hybrid 2wd, 6.0L LFA (stock dd)
    1964 Chevelle Malibu 4 door, 2003 LQ4, 06 GTO T56 swap -> https://www.chevelles.com/threads/19...-build.955866/

  3. #3
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    Quote Originally Posted by Hotwire View Post
    I've got pretty close to the same setup as you do, block, heads, large long tubes, etc.

    If you're reading 15.3 aft at WOT, DON'T go WOT any longer!! That will damage your setup quick.

    I'm having the same issues w/ stalling, but mine isn't as bad as yours is.

    What I've found and am in the process of learning myself is we both need to get our MAFs tuned properly and VE tables corrected for the setup differences. Your MAF is probably in a custom intake now as opposed to the factory plastic box. That needs to be tuned. Your VE is way off due to the cam. That also needs to be tuned.

    You can get my tune from here and also see the questions/answers I'm going through *NOTICE* I'm running 33lb injectors and LS6 intake!: https://forum.hptuners.com/showthrea...iles-histogram

    I found this thread as well. I haven't had a change to put these changes into affect, but have been working on making the changes.
    http://www.silveradoss.com/forums/to...sing-hptuners/
    Hi Hotwire, thanks for the reply! Ill take a look at your tune and see if I see similarities. I think I need work in the DFCO region really. But I don't know enough to say that for certain. I'll read up on how to tune the MAF today and see if that helps. I have a set of decapped injectors I can run with this setup that have been flowed, but my duty cycle is only in the 70's.

    Alex

  4. #4
    Tuner Hotwire's Avatar
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    You're duty cycle is in the 70s because you're aft is 15:1. You'll need to up the injector size or adjust the fuel pressure, but decapped injectors are overkill.
    *Jeff*
    2002 4dr 2wd Blazer, 06 L33, LS6 cam, built trans, etc.. SOLD
    2008 Tahoe Hybrid 2wd, 6.0L LFA (stock dd)
    1964 Chevelle Malibu 4 door, 2003 LQ4, 06 GTO T56 swap -> https://www.chevelles.com/threads/19...-build.955866/

  5. #5
    Tuning Addict 5FDP's Avatar
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    If your wideband gauge and the HP Tuners read out are not the same, you need to fix that. Otherwise any open loop tuning with your wideband to correct the airflow model and fueling will be wrong.

    Aim for stoich, not for 13 afr. If you are running pump gas, make sure that stoich (14.68) is what you are going for. Make sure that your open loop EQ ratio is 1.00 for all temps above 140-150 so that it's not hunting for a random commanded AFR.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  6. #6
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    I bent back to a stock tune and tried again. I've been learning some things and with others I'm not sure why it happens or how to correct it.

    Fixed the Wideband not logging correctly.. ground, imagine that, it's important. Now it logs correctly.

    Issues needing help or explanation:

    - When the car starts, its at a 12.5 ish AFR, after a about 3 minutes , or driving it down the street a ways, it kicks itself to 16 AFR. I don't know why

    - During driving in town, it'll go from 12.5 ish AFR to 16 AFR then climb more lean to 18-20 ish, it'll surge and buck, then go back to 12 AFR. I don't know why.

    - When I come to a stop, or let it coast lets say 50 feet to a stop in neutral, if the car is 16 ish AFR, it'll come to the stop and idle fine, if it's decided to be in the 12's for AFR, it'll die, and I'll have to continue to push the accelerator pedal for a minute until it decides to stabilize, usually kicking itself to the 16 AFR range but sometimes staying 12's.

    - Highway driving has been fine stays in mid 11's -low 13's for AFR's 1500-1700 rpm, 75 -80 MPH and during a 6th gear pull, it holds that AFR just fine. It's rich, but it's always been the same, I should just have to adjust the VE table a bit I'm thinking (once I figure out the next problem).

    - My MAP sensor isn't detected with VCM logger, but I don't have any faulty codes.

    I feel like it's almost right, but I've missed something which is why it's acting weird at times.

    Thanks for the read.

    Alex

    Most up to date tune and log file from start where I think it turns lean near 200F driving in town. Then in town coffee, highway driving, and in town again

  7. #7
    Tuning Addict 5FDP's Avatar
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    You aren't logging the MAP, so it won't show up. Easy as that.

    To answer everything else, you must calibrate the airflow model. It's only doing what it's doing because the fueling is so out of whack still. Both the MAF and VE table must be calibrated to fix to lean fueling and rich fueling you are seeing. Each has to be done separate from one another and both must be done with your wideband.

    You need to create a wideband error against the commanded AFR to fix the airflow model. The VCM scanner section has a few write ups on how to setup your graphs to log this data and make the corrections.

    Once corrected the fueling should stay right around stoich, so 14.68ish. And only under decel will it go lean because DFCO is active and it will become richer if you enter power enrichment.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  8. #8
    Senior Tuner kingtal0n's Avatar
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    I have a small side question/curiosity. Do you happen to have the two rear steam ports of that engine blocked off?

  9. #9
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    Quote Originally Posted by 5FDP View Post
    You aren't logging the MAP, so it won't show up. Easy as that.

    To answer everything else, you must calibrate the airflow model. It's only doing what it's doing because the fueling is so out of whack still. Both the MAF and VE table must be calibrated to fix to lean fueling and rich fueling you are seeing. Each has to be done separate from one another and both must be done with your wideband.

    You need to create a wideband error against the commanded AFR to fix the airflow model. The VCM scanner section has a few write ups on how to setup your graphs to log this data and make the corrections.

    Once corrected the fueling should stay right around stoich, so 14.68ish. And only under decel will it go lean because DFCO is active and it will become richer if you enter power enrichment.

    Hi 5FDP, Thanks for taking the time to reply. I thought I was logging MAP, guess I messed that up. As for the other info, I'll look into logging the airflow model both MAF and VE. Thanks for pointing me in the right direction. I'll post up what I come up with.

    Kingtal0n - It's the stock lq4 style so blocked off on the rear of the head.

  10. #10
    Senior Tuner kingtal0n's Avatar
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    Quote Originally Posted by QUA-HOON View Post
    Kingtal0n - It's the stock lq4 style so blocked off on the rear of the head.
    This is just a theory. However. I have read that the reason those are blocked in the donor vehicle is because the engine is tilted towards the rear, thus any air would move to the front of the engine.

    By swapping the engine into another vehicle without the tilt, you are risking air bubbles at the back of the head which will accumulate and create hot spots that ruin the engine.

    The fact you claim to have had issues bleeding air from the engine already further emphasize this point. The air is gone (for now) but when you run the engine a while what is stopping a new bubble from forming or being introduced (There is quite a lot of that going on) and sticking back there? I recommend you switch to the 4-corner steam port apparatus to prevent this tragedy.... as you will not have the handy "bleeding device" always connected everytime you drive the car.

    further further I have swapped a Lq4 into a chassis myself and using the 4-corner steam solution had no issues bleeding the air during the several attempts I made over the last couple years with it. It has not given any trouble. Simply running the engine you can watch the water/air bubble forth from that steam port...

    this guy
    https://www.ebay.com/itm/Ls1-Coolant...YnHP:rk:9:pf:0

    I hope I am wrong. But the cost is so small and might prevent disaster I don't see the "cost savings" worth the risk.
    Last edited by kingtal0n; 10-25-2018 at 02:50 AM.

  11. #11
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    Quote Originally Posted by kingtal0n View Post
    This is just a theory. However. I have read that the reason those are blocked in the donor vehicle is because the engine is tilted towards the rear, thus any air would move to the front of the engine.

    By swapping the engine into another vehicle without the tilt, you are risking air bubbles at the back of the head which will accumulate and create hot spots that ruin the engine.

    The fact you claim to have had issues bleeding air from the engine already further emphasize this point. The air is gone (for now) but when you run the engine a while what is stopping a new bubble from forming or being introduced (There is quite a lot of that going on) and sticking back there? I recommend you switch to the 4-corner steam port apparatus to prevent this tragedy.... as you will not have the handy "bleeding device" always connected everytime you drive the car.

    further further I have swapped a Lq4 into a chassis myself and using the 4-corner steam solution had no issues bleeding the air during the several attempts I made over the last couple years with it. It has not given any trouble. Simply running the engine you can watch the water/air bubble forth from that steam port...

    this guy
    https://www.ebay.com/itm/Ls1-Coolant...YnHP:rk:9:pf:0

    I hope I am wrong. But the cost is so small and might prevent disaster I don't see the "cost savings" worth the risk.
    Hi Kingtal0n - I too have read this. But my engine has a negative 3 degree angle on it, sloping from front to rear. I've checked as it's important for drive line angle set up. I also vacuumed the entire cooling system down and have had zero problems since. I wish I bought that tool on my first LS swap.

  12. #12
    Quote Originally Posted by kingtal0n View Post
    This is just a theory. However. I have read that the reason those are blocked in the donor vehicle is because the engine is tilted towards the rear, thus any air would move to the front of the engine.

    By swapping the engine into another vehicle without the tilt, you are risking air bubbles at the back of the head which will accumulate and create hot spots that ruin the engine.

    The fact you claim to have had issues bleeding air from the engine already further emphasize this point. The air is gone (for now) but when you run the engine a while what is stopping a new bubble from forming or being introduced (There is quite a lot of that going on) and sticking back there? I recommend you switch to the 4-corner steam port apparatus to prevent this tragedy.... as you will not have the handy "bleeding device" always connected everytime you drive the car.

    further further I have swapped a Lq4 into a chassis myself and using the 4-corner steam solution had no issues bleeding the air during the several attempts I made over the last couple years with it. It has not given any trouble. Simply running the engine you can watch the water/air bubble forth from that steam port...

    this guy
    https://www.ebay.com/itm/Ls1-Coolant...YnHP:rk:9:pf:0

    I hope I am wrong. But the cost is so small and might prevent disaster I don't see the "cost savings" worth the risk.
    Or you could just fill the block through the top or the water pump and make sure your radiator fill is higher than the engine. Air bubbles travel upward.

  13. #13
    Senior Tuner kingtal0n's Avatar
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    alright cool guys. I Just want us to all be informed- it can't hurt.
    I don't worry so much about air during filling. I'm far more concerned about air bubbles running around or being generated while the engine is running- getting trapped and unable to be 'scrubbed' (you read all kinds of weird things happening) and there is always that muttering about #7 getting hot and blowing apart. So yeah XD

  14. #14
    Quote Originally Posted by kingtal0n View Post
    alright cool guys. I Just want us to all be informed- it can't hurt.
    I don't worry so much about air during filling. I'm far more concerned about air bubbles running around or being generated while the engine is running- getting trapped and unable to be 'scrubbed' (you read all kinds of weird things happening) and there is always that muttering about #7 getting hot and blowing apart. So yeah XD
    Thanks for swinging by another thread talon to make a mountain out of a mole hill.

  15. #15
    Senior Tuner kingtal0n's Avatar
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    Quote Originally Posted by 85K5Jake View Post
    Thanks for swinging by another thread talon to make a mountain out of a mole hill.
    is it a mole hill? I don't want to find out. Nobody truly knows why #7 dies and nobody is sure if 2-corner steam port is 100% safe.
    And I don't want anyone else to find out the hard way. what does it take, 5 minutes to re-evaluate? You can't spend 5 minutes to help random people, give them ideas, shoot the shit.

    Isn't that what a forum is for?

    No one is forcing you to be here, read this stuff, you know. You are doing it to yourself... all 5 minutes of it... QQ about something relevant
    Last edited by kingtal0n; 10-25-2018 at 11:11 PM.

  16. #16
    Quote Originally Posted by kingtal0n View Post
    is it a mole hill? I don't want to find out. Nobody truly knows why #7 dies and nobody is sure if 2-corner steam port is 100% safe.
    And I don't want anyone else to find out the hard way. what does it take, 5 minutes to re-evaluate? You can't spend 5 minutes to help random people, give them ideas, shoot the shit.

    Isn't that what a forum is for?

    No one is forcing you to be here, read this stuff, you know. You are doing it to yourself... all 5 minutes of it... QQ about something relevant
    Just wanted to let you know how much I appreciate your expert opinion.

  17. #17
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    Did some MAF tuning ( about 4 pulls). it's still way out. If anything it's only got more rich which isn't bad. I can just adjust on the VE table. But the car still dies at a stop light, or if I coast it in neutral. I think there is more to this problem that someone hasn't picked up on yet. Would seriously appreciate some input on this. It's actually making MAF tuning kinda suck if I come to a stop have to bump the accelerator to keep it running or it dies unless it goes super lean. . It didn't do this before the cam swap.

  18. #18
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    The B1 O2 sensor is dead. Your VE table is populated with much bigger numbers than you'd typically see in an application like this, and yet the wideband still reads lean. (and so does the B2 O2 sensor.)

    The first thing I would recommend is a fuel pressure gauge...just to verify 58 psi base pressure.
    Then replace the B1 O2 sensor, then load the attached file. It should be a good base SD file.

    1 bar maf 6.0 (Monte ) v6 kw mod.hpt

  19. #19
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    Hello! new to this form. i am doing a stock lq4 swap and i am in need of a stock tune file due to the computer in recieved was from a 5.3l .can anyone help me out

  20. #20
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    would this file work for a stock 6.0l?