Help again w/idle settings...

Discussion in '1994 - 1995 Specific Tech' started by teal_94gt, Jul 29, 2007.

  1. I am going around in circles with this thing! I've started over with a stock j4j1 base tune with my egr&smog disabled as well as checksum base at 0. When I datalog to try to set the base idle for the throttle body airflow calculation I get very low rpm values on calcon than compared to my stock and autometer tach. I understand that there is going to be some resistance and minimal loss but I feel that 100-200 rpm is alot. Changing the idle in gear and neutral scalars does nothing as far as idle rpm changes and tb airflow calculations I have made seem to be useless as well. The damn car runs perfectly on the stock settings and idles pretty much rock solid at 800-850rpm. I am using the correct formula for tb airflow maf kg/hr x 2.205/60 and when I divide the average rpm datalogged by the tb air flow I will always get lower than the stock 676 or whatever it is value; like I usually get around 600-625rpm for idle in gear and neutral. When I do it this way it will not idle; surges bad and stalls when coming to a stop. I am also running the stock j4j1 maf curve as well. I feel like I am just setting this thing manually 100%. I was also looking for that spreadsheet to do the 10-30point conversion for the maf transfer, but the link does not work. Does anyone have one they can send me? Thanks, Justin
  2. Yes ... get a good curve in there as a first step :nice:

    Look in the STRK/MAF directory ...
    at least that is where the maf files are in the older software :shrug:

    I couldn't say for the latest software but you can call em
    up in the older software by using a button on the maf transfer
    function page that was labeled ... Load Maf.

  3. Hey, sounds like you have been fighting this for a while. Looking at your combo, you aren't very far from a stock Cobra tune (save for the cam which you don't list specs on). So using the J4J1 is a good call.

    I'd start from J4J1, cut off the thermactor and EGR, load in the correct MAF like Grady said and then see what you have.

    If you want to send me your curve I can get it converted for you.

    Double check ALL your vacuum lines. Hook a vacuum gauge on it and see what it reads and let us know. Ran codes lately?

    Feel around the back of your heads and the exhaust for any leaks there.

    Exhaust and vacuum leaks will wreak havoc on your idle.

    Idle problems suck, I feel ya on that. We can definitely get it straight though.

    Can you datalog with the wideband included in the logs? If so, post up your logs and you should get some good help from around here.

  4. Well I finally found a conversion table to create the correct transfer function. EEC analyzer does not make any changes to it at all after 2 30min datalogs of mixed driving. Atleast it does not stall anymore and idles pretty well. I still did not change the stock setting for idle in gear and neutral, just the throttle body airflow. Yep no exhaust leaks and vacuum leaks everything is put back together as close to stock as possible as far as vacuum is concerned. I have no codes appearing. If you could help me get my lc1 set-up correctly I would appreciate that also since it's way off and haven't messed with it in like 6 months. Let the help begin Thanks, Justin
  5. Good to hear. On the LC-1, are you running it in via the EGR plug or over a DataQ?

    After that, you'll need to figure out the "voltage drop". This is the different between the volts that the LC-1 is putting out and the volts that the twEECer is seeing.

    What I do is set the LC-1 to output 5V for BOTH 20AFR and 10AFR. Start the car and look to see what your twEECer is reading. It will probably be in the 4 volt range. Mine was 4.84V I believe. The reading should be steady and not fluctuating. If it is fluctuating you may have a short or a bad connection somewhere.

    Next you'll want to set the LC-1 to output 1V for BOTH 20AFR and 10AFR. Check it again on the twEECer and it will be less than 1V. Mine was about 0.82V. The reading should be steady and not fluctuating. If it is fluctuating you may have a short or a bad connection somewhere.

    Do the above and we'll pickup there with changing the twEECer or LC-1 to accommodate your voltage drop.

  6. How about a bit of a different perspective :D

    To keep it short ... I'll just touch on the high points here

    Of course ... you wanna get your wide band up and running :nice:
    For Closed Loop tuning ... I rarely used wb data :)

    I found K's to be just about all I needed to let me know which
    way to go with value changes ;)

    You can find quick but big dividends with tb airflow scalar and isc neutral
    idle airflow function points when looking for the pay off in idle success.

    Over several years, as more self tuners obtained more knowledge
    with more experience, I did about three different tuning methods to
    find a good Closed Loop tune :D

    I found the most stable results to be had from dealing with the bulk
    of changes in injector parameters :nice:

    Then I fine tuned the maf curve points just ever so slightly and then ...
    only around the idle points :)

    You could say ... I used about 95% of the original maf curve values
    for the CL portion of the curve

    It goes without saying ... After I got my CL tune like I wanted ;)

    I made good use of my wb :Word:
    For Some ...... Good Old Fashion high rpm WOT tuning :banana:
    Quickly proceeded to shell out my OEM hb :rlaugh:

  7. Please help me; today this pos stared to start and die the very first start I did this morning. It has also died comming to a stop twice also. Again the correct maf curve is loaded. eec analyzer does not change this either. What parameters should I be datalogging to watch for the dying and stalling? Oh yeah my k's are around 1.077-1.8 usually. Target a/f shows on startup it's 12:5:1, can I lean this out? Thanks, Justin
  8. What does the wideband say the car is actually hitting?

    If it is surging and dying at startup (especially when the engine is warmed up), try 0'ing out the table "base_fuel_table_cold_enrichment_decay".

    If that fixes the problem, restore the original numbers in the table and reduce the numbers in the rows that correspond to the temps where your are having the problem.


    EDIT: This will do nothing for your dying at the stop sign. If it is surging real bad there, I would suspect something is causing it to be rich if there are no vacuum leaks.

    Did you ever hook up a vacuum gauge to it to see what it is reading?
  9. Your lean :)

    Your K's tell you it is adding fuel by 8% :)

    Your lambse also confirms such by commanding that fat ratio :)

    I'd do the scalar and function tweecs we talked about above

    Then you might raise the low slope inj value by 10%
    if better but not good enough add 10% more

  10. Do this for us (otherwise we are shooting in the dark).

    Upload or e-mail to me your tune (I'll PM you my email if you don't have it) as well as a good 5-10 minute datalog of normal stop and go driving, with the parameters below.

    We'll get the data up so that everyone can see what you've got and you'll be able to get some razor sharp help. :nice:


    Upload/Email the following:
    • Tune (CCF or BIN file)
    • 10 point flow sheet
    • Datalog of 5-10 minutes of stop n' go driving

    Datalog the following:
    • Actual Load
    • Battery Voltage
    • Injector Pulsewidth - DS
    • Injector Pulsewidth - PS
    • KAM Fuel Trim - DS
    • KAM Fuel Trim - PS
    • Lambda Commanded A/F - DS
    • Lambda Commanded A/F - PS
    • O2 sensor - Drivers Side
    • O2 sensor - Passenger Side
    • MAF Kg/hr
    • RPM
    • Spark Advance
    • Throttle Position Sensor
    • Vehicle Speed sensor - MPH
    • ECT (can be swapped for EGR if you are piping in Wideband data)
  11. Tomorrow is my day off. I will get you guys a couple of good datalogs. I might try to get one in on my lunch break though. Thanks again, Justin
  12. Justin

    You most likely know this ... but ... just in case :D

    If your focus is on Closed Loop tuning

    You gotta be gentle with the skinny pedal

    Certainly no WOT :nono:

    Usually any more than 1/4 to 1/3 pedal will knock you outta CL

    You gotta keep the load down ;) ... W A Y down :Word:

  13. Here are links to Justin's datalog and tune for all the guys here to dissect. (right click and "Save As")

    I think I'll have a chance to roll through it tonite - if anyone needs his CCF in a BIN file so they can see it, let me know.


    EDIT... I had a chance to get his data out in a couple more formats... links above.
  14. Hey man, had a few minutes over lunch. Looking over your tune, I see your TB airflow is changed up to 0.91 but the Neutral Idle Airflow function is stock. When you used EECAnalyzer to generate the TB airflow for you, it should have also generated the neutral idle airflow as well.

    Hit another quick datalog with your ISC duty cycle in it - see what it is sitting around - should be around 35%ish if your EECAnalyzer calculations are good.

  15. I don't ever have good luck using eec analyzer to do the tb airflow and isc neutral idle airflow scalars. That is why I just did the tb airflow manually and arraved at
    .91 Back in my second post I think I mentinoed that I can leave all the settings stock and set the idle manually and I can achieve a 35% duty cycle; right now with this tune I have never checked yet. Wes is your isc neutral idle airflow table have 0's for the first few rows columns? This is what I usually achieve and it's what grady has on his tuning page but it has never worked right for me. I am 99.99% sure I don't have any vacuum leaks. Usually dies on startup hot or cold first couple of times. As you can see my KAM's are pretty f'ing good and the maf transfer is dead on per eec analyzer. Thanks guys, Justin
  16. Yes, my stock ISC has 0's in the first few values, that is normal. The ISC is fairly linear so it doesn't need a lot of points.

    When running your calculations in EECAnalyzer, did you have your MAF transfer loaded? It uses that to properly build the TB airflow. I converted the MAF to EECAnalyzer CSV above if you want to snag it and try doing the "TB Airflow & ISC" reset procedure outlined in EECAnalyzer.

  17. Ok Justin, I had a chance to look at your datalog and tune. It looks like the EEC just is not able to properly calculate the proper airflow needed for the throttle body and idle air controller.

    These will have to be dead on to get the car to idle that low, especially if you have a non-stock cam. And heck, depending on the specs of the cam, an idle in the 600s may just be too low? Jay could tell you what it should idle at.

    With the SPOUT and ISC unplugged and the car warm, what was the lowest RPM you could make it idle at?

    How far out from bottom is your ISC bleed screw?

    Grady - any input?

  18. Of all the time I spent teaching my self to self tune by research and
    findings from how my 95 reacted to tweecs ...........

    I spent more time with idle and low pulse width driving conditions
    of cruise and the like :Word:

    I suspect some of that was due to a very narrow lsa cam spec :)

    Now ... I said all that to let you know .......
    I would advise you to start with a idle setting of 850 rpm ;)

    Here is the deal as a new self tuner :D
    There are so many things that effect those kinds of conditions :crazy:

    An elevated idle speed will make things be more consistent :nice:
    and my reasoning for that thought is the air flow is greater
    thus the various tweecs are not so touchy.

    IMHO ... you need to focus on drivability first ;)
    That entails maf curve, airflow values at idle, inj parameters, and more.
    I would keep the idle high during all that kind of tuning.

    Then ... when things seem fairly stable ... drop it some if you wish.

    If you find things go sour with a lower idle speed ... by this time
    you've learned enough to know how to deal with what crops up ;)

    I briefly looked at that dl and I saw a LOT of K values of 1.0's at idle :eek:
    When I've seen that ... it usually means you've slipped outta CL :(

    Another thing along those lines ... much of the time ... K values very
    close to 1.0 ... the same data event shows l values a good bit fatter
    than 14.7 to 1

    I suspect you are running too lean :)

    Another thing I noticed is your MPH at times looked kinda hokey :shrug:
    It seemed to be more noticeable in the last 1/3 of the dl.
    You would see what looked like a cruise speed of 30 for several
    data events and then one like 35 followed by more 30 values.

  19. This is what I have been trying to tell you guys. I can set the idle in gear/neutral at whatever I want and the damn thing does not change. It idles right around 900-1000rpm when I have the command set to 650 or whatever it is currently. With the car warm and the isc and timing spout unplugged I can get it to idle at around 600-700 rpm. Jay recommends it ides at around 800-900. ISC screw is a few turns from the bottom. Grady-how am I suppose to richen it up?

    In eec analyzer for the isc settings, what are my rpms and vdcs suppose to be set at? What I am commanding or what? I am literally going insane trying to set the idle over and over again with no positive results. Thanks for the help guys. Justin
  20. I hear ya on the idle problems - they are quite simply the hardest issue to deal with in tuning. There are a lot of pieces that play into idling - see the thread link below for more.

    Here's what I would do. Keep your current tune with the stock values. Do a triple check and make sure you have no vacuum leaks. Look under the intake also.

    Based on Jay's recommendation, try shooting for an 850rpm idle. Also raise the scalars "Max Idle RPM at CT" (IDLRPM_ISC) and "ISC max RPM in drive" (ISCLPD)

    See this thread for some more values to check as well:

    Run through the EECAnalyzer steps to get a proper TB airflow and Neutral Idle airflow. Remember to load in your MAF Transfer into EECAnalyzer - it uses that to come up with the correct values.

    Fingers crossed that your idle problem is then much more stable.

    Next, use EECAnalyzer to calculate the Injector Timing for you. That is going to smooth out your idle further.

    Bonus points if you can correlate the LC-1 data in with your datalogs to confirm what Grady is suggesting is happening.