Tuning Cam Idle
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Tuning Cam Idle
So.. apparently there is some conflicting information out here about the "best" way of tuning up the idle on cams. Right now I'm trying to compile a list of settings that should be tweaked.
I'll go over what i've done and if it helped or not.
1) Changed the timing to 11* at idle (well that sucked and threw the p300 code so i took it back out)
2) Enabled SAS mode and adjusted the idle screw a little until the idle was around 800 rpm, the idle was still hunting but after disabling the SAS mode it was MUCH better.
3) Played around with the desired ISCV tables. It "appears" to help especially for the AC mode but the idle is still hunting.
Currently the car is very drivable fuel trims are solid, even the ISCV steps appear to be semi stable but the AFR is always hunting like crazy and my vacuum at idle is also hunting in correlation with the AFR.
So I'm assuming at this point the ISCV steps as logged by evo scan really doesn't correspond with the real ISCV point in time. I'm guessing its some kind of "target" that its trying to reach. Also while I'm at it the MAF HZ seem to be very stable they aren't bouncing around sometimes i get 47hz when the idle speed surges a little.
I'm running with S1 cams which aren't very aggressive. I was expecting these to idle near stock but they wont :P. If you guys have any experience messing with the cams please give me some tips for doing so.
I'll go over what i've done and if it helped or not.
1) Changed the timing to 11* at idle (well that sucked and threw the p300 code so i took it back out)
2) Enabled SAS mode and adjusted the idle screw a little until the idle was around 800 rpm, the idle was still hunting but after disabling the SAS mode it was MUCH better.
3) Played around with the desired ISCV tables. It "appears" to help especially for the AC mode but the idle is still hunting.
Currently the car is very drivable fuel trims are solid, even the ISCV steps appear to be semi stable but the AFR is always hunting like crazy and my vacuum at idle is also hunting in correlation with the AFR.
So I'm assuming at this point the ISCV steps as logged by evo scan really doesn't correspond with the real ISCV point in time. I'm guessing its some kind of "target" that its trying to reach. Also while I'm at it the MAF HZ seem to be very stable they aren't bouncing around sometimes i get 47hz when the idle speed surges a little.
I'm running with S1 cams which aren't very aggressive. I was expecting these to idle near stock but they wont :P. If you guys have any experience messing with the cams please give me some tips for doing so.
It should only require 8-9* of idle advance, set the desired idle in neutral to 950 or so, bump the ISC for AC off/neutral a little and it should be good. You may need to adjust the BISS with the SAS function off since its not really designed for use with cams. Set it by ear and you'll know what I mean.
Thread Starter
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From: Sacramento, CA
It should only require 8-9* of idle advance, set the desired idle in neutral to 950 or so, bump the ISC for AC off/neutral a little and it should be good. You may need to adjust the BISS with the SAS function off since its not really designed for use with cams. Set it by ear and you'll know what I mean.
When setting the BISS is the idle supposed to be steady?
And will bumping up the desired ISCV stop this idle and AFR ranging that i see?
Also since i'm in cali I'm not sure i can set the idle that high or not
to pass emissions
yeah set the BISS correctly and it wont hunt it will be set at the desired idle. Most emissions testing require the idle be below 1100 I think...1000 to be safe and you should have it.
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That buschur metal induction pipe is a serious pita to tune at idle. I would follow everything JB has suggested and see how it takes it.
Other thing to check is the ISC gear. I've seen some 03-04 have the little plastic gears cracked or broken and no matter what you try you will never get the thing to idle because it physically can't.
Other thing to check is the ISC gear. I've seen some 03-04 have the little plastic gears cracked or broken and no matter what you try you will never get the thing to idle because it physically can't.
Sounds like you need to figure out what your cam timing is on the intake an exh. Sounds like Lobe centers are very close causing your choppy idle. If you have adj cam gears you need to retard them...there have been multiple threads on retarding cam timing to get better idle... Just a thought.
Thread Starter
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From: Sacramento, CA
Update:
Well I adjusted the BISS until i was hovering somewhere around 900rpm or so and then turned up the ISCV a couple points above stock in the last two columns. The idle is definitely much improved.
I think I could be battling an issue with missfire too, one of my plug wires appears to be damaged so I've ordered up a set. Cams are fun though definitely has opened up the power band above that 5500 rpm mark.
Well I adjusted the BISS until i was hovering somewhere around 900rpm or so and then turned up the ISCV a couple points above stock in the last two columns. The idle is definitely much improved.
I think I could be battling an issue with missfire too, one of my plug wires appears to be damaged so I've ordered up a set. Cams are fun though definitely has opened up the power band above that 5500 rpm mark.
yea i have been having a little trouble as well... my a/f still hunts around like you were saying...idle drops when i clutch in occasionally... but it has to do with the ics values just havent gotten around to raising them... also i have the okada packs now... that seemed to help actually.
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From: Italy
It should only require 8-9* of idle advance, set the desired idle in neutral to 950 or so, bump the ISC for AC off/neutral a little and it should be good. You may need to adjust the BISS with the SAS function off since its not really designed for use with cams. Set it by ear and you'll know what I mean.
Newbie
Joined: Sep 2006
Posts: 41
Likes: 0
From: Italy
Sounds like you need to figure out what your cam timing is on the intake an exh. Sounds like Lobe centers are very close causing your choppy idle. If you have adj cam gears you need to retard them...there have been multiple threads on retarding cam timing to get better idle... Just a thought.
