ArKay99
July 9th, 2006, 02:13 AM
My mods are in my sig. I also installed a 2002 Z06 OS and am tuning with that. All in all the car runs great but here is the problem and I've been at my wits end trying to find the answer. I only know the symptoms.
When I start the car and let it idle, it idles perfect. I back it out of the driveway and drive to the corner, about 100ft. It's perfect. I drive normally and go through the gears to 5th and cruise for about 1500ft in 4th or 5th at 30 to 35mph and sometimes, not always if I take my foot off the accelerator and push the clutch in, like I'm rolling to a stop, the engine just dies. I have tried all sorts of combos. Adding lots of air to the throttle cracker, adding and subtracting small amounts of air to the throttle cracker, taking out air from throttle cracker all together, adding and subtracting air from the throttle follower. I have set my DAF to RAFIG, RAFIG is within +-.1 most of the time. The LTFT's are within +1 -> -4 and if I could get the car to stay running I bet they would settle to within -1 to -4.
I have done about 100 idle transition tuning logs and they are different, but not by much < .300g/s overall. There are no intake or exhaust leaks I can detect and the LTFT's track pretty evenly everywhere.
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What I have noticed is odd is this: The MAF and DYNAIR track very closely, i.e. they average close to the same, but the DESIAC_B is VERY low in comparison. If I enter the MAF values into the DAF table my RAFIG map is -3 to -4 gs/sec everywhere, and the car has a hard time idleing and won't stay lit at all when driving down the street provided I can get it going. If I use the RAFIG values they get very close and the car is very driveable except for the intermittent stalling. The intermittent stall exhibits thes symptoms. When I'm driving along at 30-35mph in 4th or 5th gear, 1200-1400rpm's, the car will go from a state where it is going along very smoothly to a state where it starts bucking against the gearing, almost like I am turning the iginition on and off rapidly. No power for approx 300ms then power, then again, and again, it's not rhythmic, but random. You can feel it and hear the engine banging against the gearing, but it's not violent. I don't detect misfires when this is happening, and my WB02 says that AFR is right at 14.6. If I take my foot off the accelerator and push the clutch in at this time then engine will stall, much like the tb blade is slapping completely shut. If I am going along and don't have the above noted symptoms, and roll to a stop, the car behaves just like stock. One other thing I have noticed when the bad stuff is happening is the idle trims and ultimately RAFIG show LARGE differences from the parked and logged values, like 1.55gs/sec, or -145gs/sec. Also, it's worse with AC on than with off. Spark is normal, although I had bumped it a few degrees in the idle area, and there is no knock retard detected.
What am I missing? Sorry for the long post. I just wanted to give as much detail as possible.
When I start the car and let it idle, it idles perfect. I back it out of the driveway and drive to the corner, about 100ft. It's perfect. I drive normally and go through the gears to 5th and cruise for about 1500ft in 4th or 5th at 30 to 35mph and sometimes, not always if I take my foot off the accelerator and push the clutch in, like I'm rolling to a stop, the engine just dies. I have tried all sorts of combos. Adding lots of air to the throttle cracker, adding and subtracting small amounts of air to the throttle cracker, taking out air from throttle cracker all together, adding and subtracting air from the throttle follower. I have set my DAF to RAFIG, RAFIG is within +-.1 most of the time. The LTFT's are within +1 -> -4 and if I could get the car to stay running I bet they would settle to within -1 to -4.
I have done about 100 idle transition tuning logs and they are different, but not by much < .300g/s overall. There are no intake or exhaust leaks I can detect and the LTFT's track pretty evenly everywhere.
---
What I have noticed is odd is this: The MAF and DYNAIR track very closely, i.e. they average close to the same, but the DESIAC_B is VERY low in comparison. If I enter the MAF values into the DAF table my RAFIG map is -3 to -4 gs/sec everywhere, and the car has a hard time idleing and won't stay lit at all when driving down the street provided I can get it going. If I use the RAFIG values they get very close and the car is very driveable except for the intermittent stalling. The intermittent stall exhibits thes symptoms. When I'm driving along at 30-35mph in 4th or 5th gear, 1200-1400rpm's, the car will go from a state where it is going along very smoothly to a state where it starts bucking against the gearing, almost like I am turning the iginition on and off rapidly. No power for approx 300ms then power, then again, and again, it's not rhythmic, but random. You can feel it and hear the engine banging against the gearing, but it's not violent. I don't detect misfires when this is happening, and my WB02 says that AFR is right at 14.6. If I take my foot off the accelerator and push the clutch in at this time then engine will stall, much like the tb blade is slapping completely shut. If I am going along and don't have the above noted symptoms, and roll to a stop, the car behaves just like stock. One other thing I have noticed when the bad stuff is happening is the idle trims and ultimately RAFIG show LARGE differences from the parked and logged values, like 1.55gs/sec, or -145gs/sec. Also, it's worse with AC on than with off. Spark is normal, although I had bumped it a few degrees in the idle area, and there is no knock retard detected.
What am I missing? Sorry for the long post. I just wanted to give as much detail as possible.