How much advance are you running?
I increased mine to about 22 degrees and that also helped to staibilised idle.
How much advance are you running?
I increased mine to about 22 degrees and that also helped to staibilised idle.
I'm at 27 degrees in the idle zones.Originally Posted by VYSSWagon
I read that 26-28 is good. I dunno.
2002 Trans Am 6sp, Hurst shifter, short stick,
!skip shift, SLP lid, Holley filter, Dynomax Ultraflow muffler, Jet Hot long tubes and cats, FRA, HP tuners, Hotchkis STB and LCAs. TEA stage 1.5 5.3 heads, Comp 220/224 114 +2, UMI Boxed SFCs
Correct me if I wrong here. The aim isn't to find a magical number and apply that figure to all applications, you need to find out what 'your' setup wants. Use the bi-directional controls and adjust timing from there. I have used idle timing IVO 20* and as high as 27*+, mine likes ~23*, IAC 40 and typical MAP of 50-51 in both open (thanks MNR-O) and closed loop for that matter all at 825rpm.
Use MNR-O's guidance for the fueling/VE and find the 'happy' value with timing and that should help a lot.
If you're are really worried about where your changes effect use the VE Mult and only change the 0% TPS value up to 1200rpm ie idle (or perhaps when backing off) BTW I run a M6 and it works a treat
Good luck
Last edited by SSUte01; 05-19-2006 at 04:22 AM.
Well at very low RPM running lean isnt bad. Also, I kept my OLFA tables stock, apart from shifting the OLFA table down a few cells so at idle kPa it read 1.0 across to the right from cold startup. The car fuels from the fuel startup OLFA table anyway, which is about 1.16 on mine.
Hi,
I'm having idle fueling issues with my 383 stroker ls1. My camshaft is a TSP Giant 248-254 112 lsa (lot of overlap) so o2 are not happy at idle. I'm in closed loop right now. I've tried to put the car in open loop from 0-1200 rpm only following MNR-0 procedure step by step but it doesn't seem to work for me. The commanded AFR in the scanner is 16.3 (This is what I want to be at idle) when I start the car and stays there until I touch the gas pedal and then It goes back to 14.63.
The only way I can run open loop all the time is with closed loop enabled temp set to 284F. I don't want it at part throttle because I want to be safe and I don't have a wideband to check my AFR. When I'm in closed loop, the car runs like stock at part throttle (LTFT are all between -4 and 0) so I want to keep it closed loop above 1200rpm. By the way, maf as been removed and i'm running in SD. MAF frequencies are all set to 0 and MAF is disconnected.
Probably that i've missed something in the pocedure but I can't find it. My EQ are all 0.90 around idle MAP (60-65 kpa). PE is also 0.90 from 0-1200 rpm. Hot and cold PE have been modified also. PE TPS activation are all 0 from 0-1200rpm. My PE MAP enable MAP is 15 kPa. LTFT are still on because I want to use them at part throttle. I know that the PCM will always run the richess AFR to be safe. There is a parameter somewhere that tells the pcm to use the 14.63 stoich even in open loop at idle but where is it???? I've tried to turn of proportionnal fueling at idle and disable LTFT but no success
Do you guys have any suggestion to solve my problem?
Thank you very much for your help
SSDION
Log the equivalence ratio PID and get back to us.
Hi,
I did the procedure another time and now it's working!!
The loged eq ratio and AFR is what I want and the idle is much better now. The only thing I have to work on is the transition from open loop to closed loop and timing. I think that I will have to ad a little bit of VE in the upper MAP from 0-1200rpm or increase eq ratio because the car has a tendency to buck like it's missing fuel when I let off the clutch from a stop. I have to spin it above 1200rpm to let off but at least it doesn't smell like pure gas at idle and drive like a stock even with this cam (248-254 112 lsa). Idle is shaky but I think it's normal with that kind of camshaft.
I think that I'll buy a wideband very soon to check everything back because the stock O2 sensors are not good for a cammed car. In the past, I've tried BOSCH 13111 O2 sensors with headers wrap to make them hotter with no success (Rich idle all the time and bad fuel mileage).
Thank you very much MNR-0 for your good tip.
SSDION
Quebec, Canada
Car won't go Open Loop
Has anyone tried this in an 04 GTO? I can't for the life of me get my car to go into open loop for idle. I've attached my tune. If anyone can take a look and tell me what I'm missing I would appreciate it.
Tim
Set your pe enable torque to 0 % and the delay rpm to 0.
Russ Kemp
I set those, and idle ltft and idles tps to 0, still no go. This car just will not stay out of closed loop and I can't figure out what it is.
Tim
P.S. Lost my login password and no email I've ever had worked for recovery so now I'm bullygoat, used to be biggnome.
Last edited by bullygoat; 05-31-2006 at 05:00 PM. Reason: forgot my latest tune
You also have to disable the STFT Openloop.
Russ Kemp
Ok, I'll try that. I'd had tried it before but that was when I still had PE enable torque at 100% and Enable RPM at 5500.
Tim
I have made all the procedures, but still when I get to a stop, the idle lows to 300-400rpm, and then recovers to 950rpm target.
I hope MNR-0 or someone can look at my hpt and see what I have miss.
Thanks in advance
Gabe
I think your "Idle Adaptive Spark Control" Tables are a bit high. If you pull spark out to fast you will overshoot your idle RPM.
Idle Overspeed vs RPM Error Table
Your current values:
0.00000 -1.49451 -5.01099 -7.20879 -8.74725 -10.00000 -11.01099 -12.00000 -13.01099 -15.01099
I run the following:
0.00000 -0.28571 -1.29670 -2.81319 -4.61538 -6.28571 -8.08791 -9.86813 -12.28571 -16.00000
Idle Underspeed vs RPM Error Table
Your current values:
8.00000 8.00000 10.00000 12.00000 12.00000 12.00000 10.00000 6.50549 3.01099 0.00000
I run the following:
15.69231 13.62637 11.69231 9.69231 7.71429 5.73626 3.91209 1.97802 0.59341 0.00000
Hmm, the initial few minutes on a cold start makes it difficult to get the car rolling, it's very unresponsive. I basically have to hold the idle between 1200-1500 and slip the clutch. Do I need to richen it up at those temps in OLFA?
Last edited by JimMueller; 06-02-2006 at 06:05 AM.
Set your PE Delay RPM to 0 and your PE enable MAP to something sane below your logged idle MAP. I dont know what your idle MAP is, but unless you have a decent cam you will be pulling more vacuum than 55kPa preventing you from enabling PE.
You need to supply an idle log logging the equivalence ratio, MAP, TPS.
If you are struggling to hold a steady idle at ANY point, whether its cold or warm start, you have an idle tuning issue (bloody obvious I know, but sometimes we need to go back to the obvious as we often overlook the wood for the trees).
Can you supply an idle log? I have attached the config I use here.
Most idle tuning issues are to do with base running airflow and improperly set TB bump-stops.
Idle is fine, it's only when I attempt to accelerate from a stop after a cold start that it chokes. I'll try to get a log by this evening.
I still cannot get my car to go into open loop idle. I have stft open loop disabled, idle proportional closed loop disabled, pe enable rpm set to 0, tps for 400-1200 set to 0, enable torque to 0, yet I still get closed loop idle. Anyone have any idea as to what is going wrong?
Tim
Post an idle scan log. Log STFT,LTFT,map,O2 sensors 1, wideband afr, tps, idle speed , commanded afr and coolant temp.
Russ Kemp
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