Adaptive idle doesn't take over
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Thanks, but I don't have HPTuners, only Tuner Pro and PCM Hammer. But you can tell me what you changed, I can look at those changes in HPTuners and make the same changes in Tuner Pro.
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The logger showed that in order to get the required MAF, I needed to give it about 18% throttle with my foot.
It also showed that the idle code was only calling for a bit less than 3% throttle throttle opening.
So I increased the throttle scaler, a lot. A bit of math based on the desired throttle area (in square millimeters) said it needed to increase from 0.014 to 0.12.
EDIT: That math was based on a bad assumption on my part - the scaler probably doesn't need to change near that much. (One of the dangers of creating my own data logger is that I'm the one testing my work.)
That not only put the PCM in to reduced engine power, it wouldn't accept a flash anymore. I had to recover it with a debugging tool, which was kind of a pain since I haven't used it for a couple years and I've changed computers in the meantime.
After that headache, I gave up on the Katech throttle body, installed the 92mm LS2 body from my previous setup, and set the scaler back, and it idled on it own with no further tuning. Now I just need to bring it down under 1000 RPM. But since the adaptive idle works now, I don't think that will be hard.
It also showed that the idle code was only calling for a bit less than 3% throttle throttle opening.
EDIT: That math was based on a bad assumption on my part - the scaler probably doesn't need to change near that much. (One of the dangers of creating my own data logger is that I'm the one testing my work.)
That not only put the PCM in to reduced engine power, it wouldn't accept a flash anymore. I had to recover it with a debugging tool, which was kind of a pain since I haven't used it for a couple years and I've changed computers in the meantime.
After that headache, I gave up on the Katech throttle body, installed the 92mm LS2 body from my previous setup, and set the scaler back, and it idled on it own with no further tuning. Now I just need to bring it down under 1000 RPM. But since the adaptive idle works now, I don't think that will be hard.
Last edited by NSFW; Oct 1, 2023 at 03:12 PM.
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Joined: Oct 2006
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From: Euless, TX
The logger showed that in order to get the required MAF, I needed to give it about 18% throttle with my foot.
It also showed that the idle code was only calling for a bit less than 3% throttle throttle opening.
So I increased the throttle scaler, a lot. A bit of math based on the desired throttle area (in square millimeters) said it needed to increase from 0.014 to 0.12.
That not only put the PCM in to reduced engine power, it wouldn't accept a flash anymore. I had to recover it with a debugging tool, which was kind of a pain since I haven't used it for a couple years and I've changed computers in the meantime.
After that headache, I gave up on the Katech throttle body, installed the 92mm LS2 body from my previous setup, and set the scaler back, and it idled on it own with no further tuning. Now I just need to bring it down under 1000 RPM. But since the adaptive idle works now, I don't think that will be hard.
I'm not quite ready to say that there's no way to make Katech's 102mm "C5" throttle body work on a C5 with tuning alone, but I have a hunch that there's no way to make Katech's 102mm "C5" throttle body work on a C5 with tuning alone. At least not with a 454. Has anyone been able to get it working with a 346?
Anyway I see now why people drill holes in big aftermarket throttle bodies. I'm not going to drill a hole in mine, but I might try running a small air hose from a new fitting on the intake tract (post-MAF) into the manifold's PCV fitting. That might create enough of a "leak" to let the engine idle with a more traditional throttle opening angle.
But first I want to enjoy the car for a while.
It also showed that the idle code was only calling for a bit less than 3% throttle throttle opening.
So I increased the throttle scaler, a lot. A bit of math based on the desired throttle area (in square millimeters) said it needed to increase from 0.014 to 0.12.
That not only put the PCM in to reduced engine power, it wouldn't accept a flash anymore. I had to recover it with a debugging tool, which was kind of a pain since I haven't used it for a couple years and I've changed computers in the meantime.
After that headache, I gave up on the Katech throttle body, installed the 92mm LS2 body from my previous setup, and set the scaler back, and it idled on it own with no further tuning. Now I just need to bring it down under 1000 RPM. But since the adaptive idle works now, I don't think that will be hard.
I'm not quite ready to say that there's no way to make Katech's 102mm "C5" throttle body work on a C5 with tuning alone, but I have a hunch that there's no way to make Katech's 102mm "C5" throttle body work on a C5 with tuning alone. At least not with a 454. Has anyone been able to get it working with a 346?
Anyway I see now why people drill holes in big aftermarket throttle bodies. I'm not going to drill a hole in mine, but I might try running a small air hose from a new fitting on the intake tract (post-MAF) into the manifold's PCV fitting. That might create enough of a "leak" to let the engine idle with a more traditional throttle opening angle.
But first I want to enjoy the car for a while.
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Thinking about this some more, I see no reason why any 102mm throttle body should need to be open 20% at idle but that seems to be the case for Katech. I mean you'd expect it to need a lower opening angle than a 92mm throttle body. I guess I should talk with Katech about whether this is normal.
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From: Euless, TX
Was that with a gen 3 or gen 4 PCM?
Thinking about this some more, I see no reason why any 102mm throttle body should need to be open 20% at idle but that seems to be the case for Katech. I mean you'd expect it to need a lower opening angle than a 92mm throttle body. I guess I should talk with Katech about whether this is normal.
Thinking about this some more, I see no reason why any 102mm throttle body should need to be open 20% at idle but that seems to be the case for Katech. I mean you'd expect it to need a lower opening angle than a 92mm throttle body. I guess I should talk with Katech about whether this is normal.
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My rant about needing to radically increase idle area stemmed from misinterpreting some numbers in my log. The new TB idles with 2.5% in a parameter (desired idle area) that I thought needed to increase to 20%.
So after I get everything dialed in with the current TB, I'll give the Katech another shot.
So after I get everything dialed in with the current TB, I'll give the Katech another shot.
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From: Euless, TX
Aftermarket large TBs have no hole and in this case no IAC. Theres no harm in putting a small hole...emphasis on small and not making the DBW work so hard to idle.
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Last edited by Fast355; Oct 1, 2023 at 11:00 PM.
DBW throttle bodies are never fully closed and do not have a hole either. All putting a hole in it does is mess with the calibrations that make it operate correctly. It is easier for me to tune it without the hole. That is all I am saying. Put a hole in it if it makes you feel better but a decent tuner will hate you for it. Making DBW idle correctly is 10x easier than with an IAC. When you put a hole in the throttle butterfly you alter the IAC flow table and that is rarely benificial and takes time and money to correct again. More than 1/2 of the idle speed control is timing anyway once the idle airflow is close to where it needs to be.
Drilling a hole in a DBW TB. 
Did I go back in a time machine to 2002? 
I've actually had to do that one time and that was with a tune that was scaled by a factor of 4 and it was a large cube motor with a blower and it just plain ran out of table so to speak and this is not that.
Did I go back in a time machine to 2002? I've actually had to do that one time and that was with a tune that was scaled by a factor of 4 and it was a large cube motor with a blower and it just plain ran out of table so to speak and this is not that.
Drilling a hole in a DBW TB. Did I go back in a time machine to 2002?
I've actually had to do that one time and that was with a tune that was scaled by a factor of 4 and it was a large cube motor with a blower and it just plain ran out of table so to speak and this is not that.
Did I go back in a time machine to 2002? I've actually had to do that one time and that was with a tune that was scaled by a factor of 4 and it was a large cube motor with a blower and it just plain ran out of table so to speak and this is not that.
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R_max_idle_area
R_max_idle_throttle_position
R_throttle_rotation
Max_idle_area
Max_idle_throttle_position
Throttle_rotation
These table might help abit. They are doubled with slightly different name and have same values. Not sure if they need to match or not id tuned.
R_max_idle_throttle_position
R_throttle_rotation
Max_idle_area
Max_idle_throttle_position
Throttle_rotation
These table might help abit. They are doubled with slightly different name and have same values. Not sure if they need to match or not id tuned.
I'm not calling the OP an idiot and I mean absolutely no offense what so ever, but what he has been posted tells me he doesn't know how. This combo would take an experienced tuner a couple of hours at the most to have running and driving well.
If I followed, he's also tuning using PCM Hammer. I have zero experience with that so I don't know if tuning it is as user friendly or has the same tables available that EFI/HPT do. Even so, if you don't do it for a living on the daily it's obviously much easier to end up fighting through something like this.