MAF effects on idle tuning?
MAF effects on idle tuning? I am desperately trying to get my idle situated since it is raining outside and I can't go driving around to work on the VE. I feel like I am turning in circles with the incremental changes...
So, here is where I am:
Idle RPMs are increased to 950, MAF is turned off, car in open loop with the fuel trims disabled...
From my obviously limited understanding, I take this as being able to directly influence everything with a few things, commanded airflow, commanded fuel input, and commanded spark.
The problem I am running into is that I can't get the car to idle at all - no matter what changes I make. I increase the Base Running Airflow in 2g/sec increments, no change. I adjust the spark advance, no change. By no change I mean the car does the same thing, I get the same readings (IAC is staying at 160+, g/sec hits the same place, etc.).
Am I fighting a lost cause trying to do this in SD? Do I need to bring the MAF back into play in order to dial in the idle?
Thanks for any thoughts.
So, here is where I am:
Idle RPMs are increased to 950, MAF is turned off, car in open loop with the fuel trims disabled...
From my obviously limited understanding, I take this as being able to directly influence everything with a few things, commanded airflow, commanded fuel input, and commanded spark.
The problem I am running into is that I can't get the car to idle at all - no matter what changes I make. I increase the Base Running Airflow in 2g/sec increments, no change. I adjust the spark advance, no change. By no change I mean the car does the same thing, I get the same readings (IAC is staying at 160+, g/sec hits the same place, etc.).
Am I fighting a lost cause trying to do this in SD? Do I need to bring the MAF back into play in order to dial in the idle?
Thanks for any thoughts.
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What software are you using, you can try emailing it to me at: tuner@1320hp.com if you're using HPTuners.
Sounds like you need to drill the throttle body hole bigger.
Or crack the throttle blade and reset the tps. Thats just where to start. I'm sure the VE table needs leaned in the idle area.
Or crack the throttle blade and reset the tps. Thats just where to start. I'm sure the VE table needs leaned in the idle area.
I've cracked the throttle blade as much as possible - to the point that if I go further the TPS won't reset to 0%. What gets me is that adjusting it from completely closed to cracked seems to have zero effect. I even went so far as to pull a vacuum hose (PCV) and used a universal fitting to adjust how much air that would let "leak" in and it didn't seem to matter...
I agree that I may need to drill the blade, just trying to make sure that is my option as some people swear there is no need and others do. The results I have from doing the above make me think that there is something else going on.
I agree that I may need to drill the blade, just trying to make sure that is my option as some people swear there is no need and others do. The results I have from doing the above make me think that there is something else going on.
2002 SS with a new 402 LS2
11.5:1 compression ratio
244/250...114 LSA cam
AFR 225 62cc heads
Kook's headers
FAST 90/90 Intake/TB
SLP 85mm MAF
42lb Racetronix injectors (48.83lb/hr @ 58psi)
255lph fuel pump
Manual transmission
Thanks a ton to Mike for helping me out - working with his input the car will idle now - it is surging a good bit (bouncing from 890-1200rpms), and the IAC is still entirely too high, but this gives me a place to start moving forward at least.
Current tune and a log of the car warming up is attached - I am definitely open to any words of wisdom.
Thanks.
11.5:1 compression ratio
244/250...114 LSA cam
AFR 225 62cc heads
Kook's headers
FAST 90/90 Intake/TB
SLP 85mm MAF
42lb Racetronix injectors (48.83lb/hr @ 58psi)
255lph fuel pump
Manual transmission
Thanks a ton to Mike for helping me out - working with his input the car will idle now - it is surging a good bit (bouncing from 890-1200rpms), and the IAC is still entirely too high, but this gives me a place to start moving forward at least.
Current tune and a log of the car warming up is attached - I am definitely open to any words of wisdom.
Thanks.
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not that im a tuning pro, but a quick look at your log... your car is real rich at idle.. have you played with your VE at all? my car has a smaller cam but less cubes compared to what you have and it likes more timing. Hates running at 11-12:1 afr at idle, which is where your around..a little better, once you get it in the 14:1 range its like night and day for me.
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Verdad Gallardo Agreed - I got some input from Russ over on the HPTuners forum and he got me going. First thing we did was to increase the idle speed a little more so there was a little more room for "error" in a sense. Timing seemed to be the biggest thing to get me going (idle timing is in the high 30's), and then continuing to massage the VE table has gotten it a bit smoother.
Keeping the AFR in the right range is helping me get the idle speed down some at this point, but I haven't had a whole lot of time to work on it in the past few days.
Thanks for looking it over and providing some insight - being new at this aspect of the car is definitely presenting a learning curve. With that being the case, all input helps me out
Keeping the AFR in the right range is helping me get the idle speed down some at this point, but I haven't had a whole lot of time to work on it in the past few days.
Thanks for looking it over and providing some insight - being new at this aspect of the car is definitely presenting a learning curve. With that being the case, all input helps me out
