Results 1 to 21 of 21

Thread: LS Stalling at Light Loads (Haltech Elite)

  1. #1
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190

    LS Stalling at Light Loads (Haltech Elite)

    My fresh build had an initial dyno tune and is booked for a few weeks' time for more refinement, but at the moment it's difficult to move around because it stalls with very light loads (2-5% throttle) and it also barely catches or stalls if I give it a rev at standstill.

    I don't know a whole lot about tuning but compared with the Haltech LS base maps it doesn't look to have much fuel at light loads and lots of timing at low rpm.

    Any thoughts on getting it to behave better?

    Click image for larger version. 

Name:	Fuel Zero Demand.JPG 
Views:	37 
Size:	160.4 KB 
ID:	104877Click image for larger version. 

Name:	Base Ignition.JPG 
Views:	44 
Size:	229.8 KB 
ID:	104878Click image for larger version. 

Name:	Base Fuel.JPG 
Views:	41 
Size:	256.1 KB 
ID:	104879Click image for larger version. 

Name:	Ignition Zero Demand.JPG 
Views:	36 
Size:	164.4 KB 
ID:	104880

  2. #2
    Purist, whats that? Jason Broadhurst's Avatar
    Join Date
    Nov 2003
    Location
    North Brisbane
    Posts
    6,406
    You can't hurt anything adding a little more fuel. It may also be throttle enrichment.

    Have a play, if your still stuck I can remote in fiddle.
    Jason Broadhurst

    Someone once asked me if they could use my mower. I said "sure, so long as it doesn't leave my yard"

  3. #3
    Registered User
    Join Date
    May 2009
    Location
    windsor nsw
    Posts
    1,189
    Needs some more idle timing to make it stable
    Just muck with the overall trim at idle to see if it wants more or less fuel. Forget about afrs just give it what it wants for a solid idle
    Last edited by bpm; 24-02-18 at 10:06 PM.

  4. #4
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    Thanks guys, I'll start by adjusting the base ignition timing then adding some more fuel for light loads. The cam has an overlap of 20 degrees with very little vacuum hence TPS based VE tuning.

    It doesn't seem right that the fuel figures go straight from zero demand of 55, 50, 45 @ 1000, 1500, 2000rpm to main table figures of 17, 17, 21 @ 1-5% loads.
    Last edited by neil_se; 25-02-18 at 08:26 AM.

  5. #5
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    I increased the zero demand ignition in the idle range to 12 degrees and it was idling fairly stable at 1000rpm.

    It seems that tuning would be simpler if the 0% throttle range was just in the main table rather than using the Zero Demand tables?

    I might try adjusting the idle control stall offset and decel so it doesn't drop so low before struggling to 'catch' it. I should also mention it has 12lb aluminium flywheel so the revs drop pretty quick.

  6. #6
    sack riding 10sec rx7's Avatar
    Join Date
    Nov 2001
    Location
    Sydney
    Posts
    17,806
    where did that map come from?
    im a cunt
    and apparently i dont know shit...

  7. #7
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    From the tuner. I had all the Haltch base maps loaded for first start up but it wouldn't rev at all.

  8. #8
    sack riding 10sec rx7's Avatar
    Join Date
    Nov 2001
    Location
    Sydney
    Posts
    17,806
    very odd to be using that on a LS streetish engine...
    im a cunt
    and apparently i dont know shit...

  9. #9
    Purist, whats that? Jason Broadhurst's Avatar
    Join Date
    Nov 2003
    Location
    North Brisbane
    Posts
    6,406
    Check your TPS calibration too. If it's using the zero demand map because it thinks your TPS is closed then you will run out of fuel quick smart. Then you exceed the TPS "dead band" and it starts to read and runs OK, ie a little more throttle than "just off throttle"

    The timing looks ok to get a car moving around the block.
    Jason Broadhurst

    Someone once asked me if they could use my mower. I said "sure, so long as it doesn't leave my yard"

  10. #10
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    The TPS reading seems to match up to the pedal position ok. I've booked the tuner to come have a look tomorrow or Friday and make some adjustments.

  11. #11
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    The car wouldn't even start yesterday so I checked the plugs and they were all fouled. I put in a new set and I made some adjustments myself today that improved things greatly:

    - Turned of closed loop at low rpms
    - Dropped the zero demand fuel 800-1500rpm to around 30
    - Increased the idle timing to 12 degrees
    - Fine tuned the idle decel values

    It now revs smoothly with light throttle, catches the falling rpms and stabilises quickly, and idles stably around target rpm.

    Video from earlier this afternoon before I adjusted idle settings.


  12. #12
    Registered User
    Join Date
    May 2009
    Location
    windsor nsw
    Posts
    1,189
    Thatís running way too fat at idle and light throttle to my ear
    Sounds fucking tops for a Mazda tho lol

  13. #13
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    That's where I just don't have enough experience or comparables to know how low the fuel load should be at idle without the wideband to guide me.

  14. #14
    Purist, whats that? Jason Broadhurst's Avatar
    Join Date
    Nov 2003
    Location
    North Brisbane
    Posts
    6,406
    I've done big posts on how to setup idle fuel and air.

    Basically fix the idle valve and adjust fuel up and down till it pulls the most rpm and vacuum.
    Jason Broadhurst

    Someone once asked me if they could use my mower. I said "sure, so long as it doesn't leave my yard"

  15. #15
    Opens
    Join Date
    Nov 2001
    Location
    One street away from Guido's den of sin
    Posts
    24,302
    Quote Originally Posted by neil_se View Post
    That's where I just don't have enough experience or comparables to know how low the fuel load should be at idle without the wideband to guide me.
    While it wont help you now, you should grab one of these. $233 AUD delivered.

    https://www.amazon.com/AEM-30-4110-U...9949712&sr=8-1

    No it wont be canbus but will function perfectly using good old 0-5v input. I have 2 of these and they both work excellent for lean cruise and spot on idle AFRs. Rig it up with engine protection and it may even save you an engine in the future as well.

  16. #16
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    I have a wideband, it's just no use at idle while the cam overlap is pulling fresh air through the exhaust valve giving lean readings.

    Thanks Jason, I'll have a look back through your posts tonight to see where I can fine tune it. I watched some HP Academy videos on idle tuning the Haltech yesterday which gave me some good pointers on getting stable idle but it didn't address the fueling. Vacuum at idle is only -40 to -50kpa and it doesn't seem to change much but I'll have a closer look.
    Last edited by neil_se; 02-03-18 at 10:15 AM.

  17. #17
    Opens
    Join Date
    Nov 2001
    Location
    One street away from Guido's den of sin
    Posts
    24,302
    Ahh fair enough, the fouling spark plugs is what me think otherwise. carry on.

    Edit - as Jason has pointed out getting the idle motor functioning well will solve half your problems. My overcammed VQ30 was a right PITA to sort idle with the Haltech but got sorted in the end.
    Last edited by psi999; 02-03-18 at 11:21 AM.

  18. #18
    sack riding 10sec rx7's Avatar
    Join Date
    Nov 2001
    Location
    Sydney
    Posts
    17,806
    its DBW isn't it?
    im a cunt
    and apparently i dont know shit...

  19. #19
    Purist, whats that? Jason Broadhurst's Avatar
    Join Date
    Nov 2003
    Location
    North Brisbane
    Posts
    6,406
    I expect so.

    The below is for fuel and ignition. Then you have to setup the idle control steps/duty values. In an elite, the same tables are used and then just cleverly emulated by the DBW throttle's first 10-15% travel.

    For instance, the idle base duty table is given as steps for any given engine temp. If the engine is hot and at 80 degrees, the value in that cell will be the % the idle control will go to and then adjust from there using closed loop. If this value is low, the engine will be low rpm after throttle application, and then closed loop will increase after a few seconds. It's better to have these values high and close loop bring it down.

    From another thread http://www.performanceforums.com/forums/showthread.php?67293879-Little-niggling-ECU-tune-issues-thread&p=841999398&viewfull=1#post841999398
    Quote Originally Posted by Jason Broadhurst
    Tips for the best idle possible.

    Turn closed loop fuel and idle off for tuning - this goes for all tuning really
    This must be done with an engine coolant temp of 80 degrees
    A wideband isn't even used for this process

    Fix idle valve value to run exactly at the 1000 rpm column (idle valve value will require constant changing)
    You should now be on the 1000 RPM column, maybe between load points or right on one
    *Adjust the fuel cells being used for the fuel calculation until you reach the highest vacuum reading obtainable
    *Adjust the idle valve value as the idle speed would have changed from 1000
    Repeat the above two steps for the 1000 rpm range, adjusting the fuel and the idle valve. Highest vacuum will be achieved at the same time you require the least amount of idle effort
    Turn on all engine loads you can (lights, fans, aircon, turn the wheel to full lock and hold it etc etc) This will change the load/MAP cell being sampled
    Adjust the idle valve to maintain the 1000 RPM tuned for above, but it will now be a greater MAP reading (less vacuum)
    Tune for this load cell/s

    Fix the idle valve at all obtainable RPM, as low/high as possible. Remember, it might not idle at 500 RPM because it is poorly tuned, so work on it and try to maintain an idle even at 500 RPM. It will help obtain your cranking injection timing.

    If you are unable to obtain the 500rpm band because of throttle not sealing or any other air intake, you probably should look at the setup because with a fully closed throttle most engines should stall completely. Even so, if yo uhave a perfectly tuned 1000 RPM column, getting to half way to the 500 RPM column and idling at 750 will result in any error purely being in the 500 RPM column.

    An ECU interpolates linearly between two cells, so if 1000 RPM error is 0, and you have an error of 2 at 750 RPM, the error at 500 RPM will be 4. Using this theory, you can nail your 500 RPM column without even being reaching it, making your 800 RPM idle spot on.

    Repeat the tuning steps with timing as well. Any smooth running interrupted by a slight dull sound and RPM drop is typically too much timing. Peak vacuum may include some of these pops and inconsistant RPM, so just back timing off until it runs smooth.

    Tuning VE and using the target AFR value is done similarly, you just set the targets to 14.0 and tune each load point to match 14:1, and then adjust the targets to the peak vacuum reading as above. Assuming you have your lag times, VE table, injector flow and engine CC spot on in the ECU, changing the target AFR is perfectly reflected in the o2 sensor readings.

    Remember peak vacuum for a fixed air intake = peak engine performance/efficiency = happy days
    Jason Broadhurst

    Someone once asked me if they could use my mower. I said "sure, so long as it doesn't leave my yard"

  20. #20
    Registered User neil_se's Avatar
    Join Date
    Mar 2003
    Location
    Toowoomba
    Posts
    1,190
    That's perfect. I had a read back through your posts on the weekend and had intended to try that process, before I destroyed my lithium battery yesterday. Now just awaiting a replacement.

    I'm just running cable throttle with Edelbrock body along with an aftermarket pedal box. I hadn't originally planned on using the Haltech and but I may change to DBW at some point in the future when I can afford a sequential box.
    Last edited by neil_se; 05-03-18 at 08:15 PM.

  21. #21
    Purist, whats that? Jason Broadhurst's Avatar
    Join Date
    Nov 2003
    Location
    North Brisbane
    Posts
    6,406
    Oh that's fine too. Crack the throttle stop screw a few turns and then run timing idle control.
    Jason Broadhurst

    Someone once asked me if they could use my mower. I said "sure, so long as it doesn't leave my yard"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •