See how this one feels.
1981 GMC Caballero Tune-1.4.hpt
See how this one feels.
1981 GMC Caballero Tune-1.4.hpt
Log: 1981 Caballero log9.hpl
Looking pretty good so far this time. Bogging from idle is a bit worse than before. Is there a way a small amount of fuel can be added when I press the gas from a a stop? I know some carbs have a fuel squirter to help with off idle acceleration, is there a PCM evolution of this anywhere in the settings?
Tweaked some of the lean areas on MAF and VVE. Also, tried some new PE settings along with zeroing out the timer. Let me know if this helps with the bogging. To answer your question; PE settings should help with that and I would imagine some transient tuning would help as well but i suspect most of your issues will be solved by dialing in the airflow models; VVE & MAF.
1981 GMC Caballero Tune-1.5.hpt
Last edited by LS ROB; 07-16-2024 at 08:44 PM.
1981 Caballero log10.hpl
Heres another log. I believe im comfortable to start tuning a little bit on my own to help the idle. I still am yet to figure out the hang it does while coasting or decelerating from park.
Awesome! Have at it man. I tweaked MAF & VVE and also pulled some BRAF to see if it helps any with the coastdown idle hang. At what rpm are you seeing it? 12-1600rpm? Also, if you could get a pretty good log with normal driving and no WOT pulls, that may help dial in the VVE more. It still needs a good bit of attention. 1981 GMC Caballero Tune-1.5 braf.hpt
Heres a log with normal driving. I multiplied the pe EQ ratio by 1.1 and it seems to had made the off-idle transition a bit smoother. Also Idle hang still happens. it usually sits around 12-1600 like you said when i'm coasting in neutral.
1981 Caballero log11b.hpl
Hey man, see if this one helps with idle hang at all. You may want to copy over the changes you made to your PE settings before writing this one. Try to get around a 30 min log next time.
1981 GMC Caballero Tune-1.6.hpt
Idle hang is still present. Also It seems when I try to upload a log longer then 25-27 minutes it will not work
Heres a longer log to go on top of that. It seems that when I upload files longer than 30 minuets they do not want to register on the upload tool. 1981 Caballero log12.hpl
Ok, I'll work with this one. I sent you a DM, IM, PM, or whatever the kids call it now days. I'll check it out and update this msg whenever I make changes.
****Attached is the changes made from your most recent log. Are you getting the hanging throttle in all gears or just neutral? I took out 5% airflow from the neutral 12-1600 range. This should make some sort of a difference to see if were on the right track. Tweaked lean areas on VVE & MAF.
1981 GMC Caballero Tune-1.7.hpt
Last edited by LS ROB; 07-28-2024 at 11:05 PM.
The idle hang seems to be most evident in neutral. Although I believe its also active in gear as well. It seems as long as the car knows its moving, it artificially raises the rpms.
I see. Just try that 1.7 tune whenever you get a chance and see if it helps.
Heres another log. Car still does the idle hang same as usual. I added a bit more to the P.E (I multiplied by 1.2 instead of 1.1) and it helped with the off idle hesitation, but when I cold start in the morning it hesitates a bit. Also, when I go up a hill under high load, (around 40mph most of the time, in 4th gear) the car will begin to bog. When it begins to do this, I drop it down to 3rd and it stops.
1981 Caballero log13.hpl
Have you gotten gas anywhere different lately? The previous log shows the trims alot more happy. This one looks lean all around.
Something weird. You are driving and the acc pedal is at 36.1% steady, spark is at 27 degrees and drops to 4 degrees and then back up to 20 degrees, pedal never moves. Here is the chart. STFT's are around -2 and don't change much. At 2800 stft's show about 10% lean with a little blip of the gas.
2000 Camaro SS 2015 L83 port injected, Whipple 3.0, 4L80E, 8.8 Ford
2013 Silverado 5.3, 6L80k 8.8
Ive only ever got gas from shell and circle k stations. I always get regular 87. Typically I try to go to the cheaper ones around town, but Ive never gone to a sketch hole in the wall place knowing the gas will be lower quality.
Thanks for tuning in Lakegoat! I'm not entirely sure whats going on there with the spark. I do know a little bit after that drop in spark, the car began to bog. I was accelerating up a hill.
Update, the hesitation is still present after driving the car awhile with the 1.7 tune. How do I tell if an area in the tune is lean regarding VVE and MAF? Do I just keep adding to either one of them until it feels right? (to state it simply)
You make corrections depending on what the fuel trims say. Positive numbers means its lean and adding fuel, negative numbers indicate rich and pulling fuel. In my opinion, each log should be a minimum of 20min of driving in order to make adjustments. The longer the drive the better. It seems you do have some sort of issue going on due to the way the VVE table is shaping up; what that is, i don't know. Adjusting PE is mainly for WOT enrichment, not sure id try adjusting it to get rid of the bog you feel.
Would the absence of the neutral safety switch possibly contribute to the idle hang issue? I?ve noticed when I?m making a log and I shift into neutral or park, the vin suite states Im still in drive, even though the transmission itself is in park/neutral.
Normally, idle hang is an indication of too much BRAF. Post up the most recent log and tune.
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