ArKay99
September 11th, 2005, 02:11 PM
I have done the Idle Transition tuning as described in the above thread and the car idles very well at first after a tune. But after a while the idle will dip to 400 rpm and then oscillate back and forth between 800 (my idle rpm's) and 400 after driving for a while. When I look at a scan then the DESIAC_B and MAF values are about 2 to 3 grams lower than what is in the tables. I have been able to get the car to idle pretty well with the idle dip not so severe but I have my Idle Air at 80C at 9.06 and 60c is 10.3, etc. The IAP is 12.3 at 40C and 14.44 at 20C. These values seem pretty large though. What will happen is I start the car with the colant at 80C and the DESIAC_B will be right around 9.06 or maybe a little more and then it will slowly drift down to around 7.3g/s. I have also noted that the DESIAC_B and logged MAF values are ALWAYS at least .5 to 1 gram different with the MAF values always being lower. I have tried adding air to the fan IAC correction cells and changed the values in the Idle learn Drive Limit high and low and Idle Learn A/C Limit high and low.
I have checked for vacuum leaks on both my intake manifold and TB to intake and also all my air intake points. The car idles pretty well, but I would like it to stay consistent, at least for a couple of drive cycles. One other thing that drives me crazy is, After a tune, the car runs beautiful while driving even in 6th gear at 35 mph and lugging the motor at 900 rpm's. After about a mile or so it feels like the fuel cuts off momentarily and the car just bucks for a second, actually it's like a soft bang, but feels like the motor has just shut off for a couple of revs, then fires back up. It is an event of only about 1 or 2 revs at most, but it is certainly felt.
The car specs are: 99 C5 85mm descreened and recal'ed MAF, VaraRam, MW90mm TB, FAST 90mm intake AFR 205's milled .030" on Cometic .040" gaskets, 30lb SVO injectors, 224/228 .581"/.588" 112lsa installed +0, Kooks headers, hf cats, aand xpipe, and Borla Stingers. Drive train is a SPEC stage 3 an aluminum FW, 4:10's. I have tuned the VE and cal'ed the MAF and my LTFT's are within 0 to -.5 everywhere.
I have checked for vacuum leaks on both my intake manifold and TB to intake and also all my air intake points. The car idles pretty well, but I would like it to stay consistent, at least for a couple of drive cycles. One other thing that drives me crazy is, After a tune, the car runs beautiful while driving even in 6th gear at 35 mph and lugging the motor at 900 rpm's. After about a mile or so it feels like the fuel cuts off momentarily and the car just bucks for a second, actually it's like a soft bang, but feels like the motor has just shut off for a couple of revs, then fires back up. It is an event of only about 1 or 2 revs at most, but it is certainly felt.
The car specs are: 99 C5 85mm descreened and recal'ed MAF, VaraRam, MW90mm TB, FAST 90mm intake AFR 205's milled .030" on Cometic .040" gaskets, 30lb SVO injectors, 224/228 .581"/.588" 112lsa installed +0, Kooks headers, hf cats, aand xpipe, and Borla Stingers. Drive train is a SPEC stage 3 an aluminum FW, 4:10's. I have tuned the VE and cal'ed the MAF and my LTFT's are within 0 to -.5 everywhere.