For the startup bug, or to try to cure something else?
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To cure your strange surge.... I've looked over your tune a bit and couldn't find anything too strange. So try a Write Entire just for reassurance.
I tried the write entire, didn't make any difference on my car.
I just removed the Vararam intake (not pleased with that intake for MAF readings and I suspected some of the surge was turbelent MAF readings) and put in a Halltech...it's certainly different now. I'm still re-tuning, not done yet, but getting better. I'll spend some time with it tomorrow, had to finish up a tune in a CTS-V for someone else today and didn't work on mine as much as I wanted to.
My car is continuing to thoroughly piss me off. Anybody want a 2010 Camaro SS? Makes great power and torque, gets great gas mileage and surges randomly for some reason that I can't figure out.
What's the price?
I think you are experiencing the same problem I have with my cammed LS7 powered 67 Camaro. It appears that at low speed and low load, it switches back and forth between the main spark table and either the idle or coast down tables. I haven't gotten a good answer on why or what causes the switch, but I am going to try a few things when the weather clears up and I find some spare time.
Check this out. http://www.hptuners.com/forum/showthread.php?t=40636
Certainly does sound similar. $28,500
It's cam reversion.
Run open loop and make it rich, or pull a bunch of timing.
The switch is caused by the PCM's spark smoothing algorithm. Disable M6 spark smoothing and it will stop flickering, but the bucking will remain.
does it do it in speed density mode?
Yes it does it in SD too. I've disabled spark smoothing, and I can still see the spark swinging in sequence with the surge. I don't know why it's not constant.
You could try straightening this mess up some.
That timing table looks fine.
You aren't as particular with them than I am with mine.
There is zero need to have them that smooth. You may be leaving power on the table at part throttle with all that blending.
Lol no Dave, 23* and that's on my blower car that runs pump gas ;)
I don't have any timing surge though. That's for sure.
Ok.
Sarge, I currently have a surge in my Z06 at a very specific operating condition from the swing of closed loop operation, but otherwise, mine is butter smooth. Some setups just have odd operating conditions that are really affected by the changing fueling in CL.
It's not a stock timing table...but it's no more or less smooth than the stock timing table was...and the car behaves exactly the same with respect to the surge with the stock table as well.
Your car also has an automatic transmission, which makes for a very different feel in the drivers seat at specific loads...including some RPM/load situations actually being impossible to hit with the auto, where you wind up driving in them all the time in the stick.
I tried open loop and it does smooth out some...maybe it is the closed loop fuel oscillation...I didn't have enough time to drive it more and see for sure, and I don't remember from the last time I was in open loop and looking at my VE and MAF stuff.
Just going by what you said.^ If you have a timing surge, use a common number for your cruise cells, smoothe it and apply that section to your idle spark table to prevent oscillation between the two during cruise. (only from 1,000-2,000 RPM though for the corresponding cruise Airmass.)
And sure there is, with an auto car for street tuning I'll manually lock the converter in every gear when driving around so I can increase engine load at low rpm. Besides, I have a Magnacharger and it starts making full boost at 60 percent throttle, which is why my main spark table drops into lower timing very quickly.
Try it, if it works yay. You'll love your car. If not, fuck it, we'll try something else.
I understand your point...but when I see the spark swinging, the MAP/MAF/ETC are not moving...so it's not moving around in the spark map...I've been working on it the past few days, but no solution yet...getting better/closer though.
I'm seeing a similar issue...probably the same issue. Fairly constant air charge, light pedal engagement taking off from neutral to 1st gear on my manual car. I've been through all the spark tables and nothing matches the delivered spark when these dips are occuring. Logging "Idle Base Advance" claims that the base idle wants to be 3.5deg even though my idle base advance table is somewhere in the 20's. That makes me believe there must be another idle spark table we don't have access to in HPTuners.
The only thing I haven't tried yet is zeroing out the AC torque reduction, but since torque management is disabled, I would think AC reduction would also be disabled. I'm trying this tomorrow. For those of you who don't understand why AC reduction would play while your AC is switched OFF, let me see if I can explain:
In the OE calibration world we have what's called a torque reserve. You know that turning on the AC is going to apply a certain amount of torque against the running engine. This torque draw on the engine will decrease the engine's RPM as it engages. You can use a calibratable relationship between spark advance and torque efficiency to compensate for this torque. Well, if you know where MBT igition timing is located, you intentionally retard the timing from MBT by an amount which decreases your engine's torque output. This is ONE reason why if you datalog ignition advance on a modern car at idle, the spark value is very retarded. Now when you hit the AC switch on your dash, the spark will ramp in back towards MBT to try and increase the engine's torque output simultaneously as the AC compressor begins to load the engine. The same holds true for accessory loads for those of you with high current loads on your alternator.
Moral of the story is that spark retard may already be in place before you ever turn on your AC.