Everyone with SD tune issue: VERY lean on starts after certain time delay.
04-03-2006, 12:31 AM
#81
in my OS i dont have those corrections to change AFAIK. i have logged all that, chagned timing, looked for something to suddenly change, ect, ect, ect and nothing has shown from it yet. i have spend hours looking through data, logging and logging, with no help. thanks for the ideas, all worth revisitings but i think a majority of my issue is in the OS and some things it does not utilize like the new ones, hopefully ill find that out soon but i will post up anything i find out.
also there are times it wont richen up for a while, and im talking about 10 min, then it falls in line, very inconsistent. also when i log and make changes its after a hot restart and all of this crap has went away and idle is back to where it should be. i think you are on the right track with your thinking, but like i said, i dont have some of that to adjust until i upgrade the OS.
also there are times it wont richen up for a while, and im talking about 10 min, then it falls in line, very inconsistent. also when i log and make changes its after a hot restart and all of this crap has went away and idle is back to where it should be. i think you are on the right track with your thinking, but like i said, i dont have some of that to adjust until i upgrade the OS.
04-03-2006, 07:01 AM
#83
Originally Posted by TAQuickness
what are you looking for you can't find? have you looked at a later OS to confirm it there?
04-03-2006, 07:34 AM
#85
Originally Posted by oztrack
If IAT says the temp is hotter than what the engine is really sucking - this would cause leanness.
nope not at all, i put the IAT in a cup of ice and plugged it up, it read 40* on start up on a 75* day and the car was still lean.
04-03-2006, 08:58 AM
#86
Originally Posted by WS6FirebirdTA00
yeah its there in the 02 OS and guys with it dont have the problem as bad as i do, Steve said his is only off by a hlaf a point to a full point
04-03-2006, 10:20 AM
#88
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Originally Posted by white2001s10
Are you comparing PW's to see if they are decreasing?
Last edited by white2001s10; 04-03-2006 at 11:23 AM.
04-03-2006, 02:24 PM
#91
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Originally Posted by Haans249
HAHAHA, phantom fuel trim cell changes are a common thing that I've been noticing lol. Mine will jump into cell 21 when transitioning to idle for some reason until i come to a complete stop....haven't figured that one out yet lol. 
Have you tried redefining a few of the learn cells?
People running very large cams will probably need to do this.
If for some reason the PCM doesn't see the engine meeting the requirements for idle mode, then this could be the problem.
For some reason your idle may be sitting on the tail-end of another cell while you're seeing the lean problem.
There's a lot of code in there for idle and I'm sure it's not all shown to us.
I'd start doublechecking things like the TPS cut-off for idle mode, and the cell boundaries.
I've never had this idle problem, but I've also never ran long duration camshafts either, so I'm thinking that's a possible cause. The last SDOL car I did idled at 650 RPM and pulled close to stock vacuum & had no problems at all.
04-03-2006, 05:06 PM
#92
Originally Posted by white2001s10
Have you tried redefining a few of the learn cells?
People running very large cams will probably need to do this.
If for some reason the PCM doesn't see the engine meeting the requirements for idle mode, then this could be the problem.
For some reason your idle may be sitting on the tail-end of another cell while you're seeing the lean problem.
There's a lot of code in there for idle and I'm sure it's not all shown to us.
I'd start doublechecking things like the TPS cut-off for idle mode, and the cell boundaries.
I've never had this idle problem, but I've also never ran long duration camshafts either, so I'm thinking that's a possible cause. The last SDOL car I did idled at 650 RPM and pulled close to stock vacuum & had no problems at all.
People running very large cams will probably need to do this.
If for some reason the PCM doesn't see the engine meeting the requirements for idle mode, then this could be the problem.
For some reason your idle may be sitting on the tail-end of another cell while you're seeing the lean problem.
There's a lot of code in there for idle and I'm sure it's not all shown to us.
I'd start doublechecking things like the TPS cut-off for idle mode, and the cell boundaries.
I've never had this idle problem, but I've also never ran long duration camshafts either, so I'm thinking that's a possible cause. The last SDOL car I did idled at 650 RPM and pulled close to stock vacuum & had no problems at all.
Adrian
04-03-2006, 10:48 PM
#93
Log the PID IAC-Final Airflow, I noticed that during these lean warm starts, that the final airflow value would decay slowly down to normal, perfectly coinciding to the lean condition, and while logging ALL the other IAC pid's they were all at zero....so this very much points to a table somewhere that we aren't seeing that is allowing too much air and decaying on a warm restart. At the exact time the lean condition went away the final airflow decayed down to normal. I also noticed that under OLSD, the calculated airflow lbs/min is much higher then the IAC final airflow, in my case about .5 lbs/min. Just an observation.
I'm still working on the issue.....
Adrian
I'm still working on the issue.....
Adrian
04-04-2006, 06:35 AM
#95
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i have had a problem with hptuners and it was a really weird bug. i would tune it without touching the idle rpm nor the idle air flow. and when the car is started everything was okay untill u press the a/c button the idle would go to 3000rpm . this problem only occured with one specific car . all the other cars i have tuned of the same model didn't have the problem. i am just saying that u could be the unlucky model if u know what i mean. make sure its not a bug first. then start solving the problem cause if it is a bug you will never get anywhere.
04-05-2006, 09:50 AM
#97
now we need to find out why, maybe some of the dynamic airflow settings. ill have to look through it, its very odd.
still on a cold start though in my car its leaner at idle than part throttle. part throttle gets closer to commanded, but maybe that has to do with some of the soak time things over the 14400 seconds since thats only cold start it does this. im going to check this 2000 rpm thing again today on the way home, first time i tried it it worked so im going to see if it does it again cause the car will sit longer.
still on a cold start though in my car its leaner at idle than part throttle. part throttle gets closer to commanded, but maybe that has to do with some of the soak time things over the 14400 seconds since thats only cold start it does this. im going to check this 2000 rpm thing again today on the way home, first time i tried it it worked so im going to see if it does it again cause the car will sit longer.