Idle Airflow Question
Idle Airflow Question OK, probably a pretty noob question.
I've recently installed a cam (23x/23x 112LSA). Car has been running pretty good, but has some slight idle issues. When cold, if I come to a stop, the idle will rapidly fluctuate between 1000 and 500 RPMs, and sometimes stalls. As soon as it's warm......idle holds steady around 850.
I think the issue is in the idle airflow tables (both P/N and inGear). I've used the scanner to record both the parameters, and it seems that even though I think I've gotten the numbers close, the car seems to run worse than before. Plus, when I adjust the values, the new recorded ones seem to shift a bit. Is this something where I just have to rinse and repeat to get the numbers dead on? Also, during logging, the airflow values change per ECT cell value, generally decreasing as the car warms up. (Example, at 212°F, starts off at x and decreases). Should I use the higher or lower values?
Now, I also want to mention that I still need to do the full tuning. I wanted to get a bung welded on for the wideband setup. I saw that there was some procedure for disconnecting the narrowband and running it off the existing bung. Can someone tell me how to do that?
Thanks.
I've recently installed a cam (23x/23x 112LSA). Car has been running pretty good, but has some slight idle issues. When cold, if I come to a stop, the idle will rapidly fluctuate between 1000 and 500 RPMs, and sometimes stalls. As soon as it's warm......idle holds steady around 850.
I think the issue is in the idle airflow tables (both P/N and inGear). I've used the scanner to record both the parameters, and it seems that even though I think I've gotten the numbers close, the car seems to run worse than before. Plus, when I adjust the values, the new recorded ones seem to shift a bit. Is this something where I just have to rinse and repeat to get the numbers dead on? Also, during logging, the airflow values change per ECT cell value, generally decreasing as the car warms up. (Example, at 212°F, starts off at x and decreases). Should I use the higher or lower values?
Now, I also want to mention that I still need to do the full tuning. I wanted to get a bung welded on for the wideband setup. I saw that there was some procedure for disconnecting the narrowband and running it off the existing bung. Can someone tell me how to do that?
Thanks.
Timing If you think you have your airflow tables down pretty good might want to look at some of your spark control tables, also whats your fuel trims look like if your to rich can also cause that, and like you said may need tuned to correct the issue.
TECH Fanatic
Joined: Feb 2004
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From: Lexington, KY
You really need to get the wideband hooked up to dial in your AFR. And make sure your IAC counts are not hitting 0 or way high. Once you have all this dialed in along with your idle airflow tables, look at your base spark tables. I'm not sure what your tuning with but with EFI live, while your logging you can watch the tune file to see what cells it is hitting while the idle is fluctuating. If there is a big difference in the value of the cells, it will feed the surge. And you might need to back off the timing from factory a bit. Also watch the throttle cracker and follower activity, might need to work on those.
Thanks,
I think first step is to get the wideband hooked up. IAC counts are about 120-150, which many have told me here that isn't too bad for a cammed car. I have some guidance (Cpig's guide) that likes to see them in the 80-90 range, but I couldn't get them lower without exceeding that magical .60V range.
FYI, I'm using HPTuners.
I think first step is to get the wideband hooked up. IAC counts are about 120-150, which many have told me here that isn't too bad for a cammed car. I have some guidance (Cpig's guide) that likes to see them in the 80-90 range, but I couldn't get them lower without exceeding that magical .60V range.
FYI, I'm using HPTuners.
I chased my tail around the raf and trying to tune my ve at idle and i would get close but then any changes would make it worse finally i found this http://www.hptuners.com/forum/showthread.php?t=5585 on hp tuners and i dont know if its wrong or right but the car idles perfect at 800 dosent stall or drop when coming to a stop, dosent loose rpm when i turn the wheel full lock, i am finally happy with it. oh yeah cam is a 230/234 110
I chased my tail around the raf and trying to tune my ve at idle and i would get close but then any changes would make it worse finally i found this http://www.hptuners.com/forum/showthread.php?t=5585 on hp tuners and i dont know if its wrong or right but the car idles perfect at 800 dosent stall or drop when coming to a stop, dosent loose rpm when i turn the wheel full lock, i am finally happy with it. oh yeah cam is a 230/234 110
