IAC counts on a modded '96?
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
IAC counts on a modded '96?
For those of you that have '96 (please, no OBDI procedures) how do you set your IAC counts if you have a larger tb, heads and cam? Do you set the tb blades jut slightly open? If that isn't enough air do you open them more? etc,etc,etc.
I've fooled around with this and I'm still lost on how to get this idle squared away. I can get it close but it still just doesn't seem right. Either it idles fine when in gear and not so fine when out of gear or vice versa. Makes me want to get a six speed! I think my problem is I don''t know the range the counts should be at and I've tried a bunch of settings. Is it 32 at idle? If so is this at the desired idle rpm? How do you set that, with the tps disconnected? Can the counts at idle be in a prefered range? If so what is that range?
If anyone has a procedure on how they get their A4 car to idle correctly in Park and then when you put it in gear they still have a decent idle I sure would like to hear it. Thanks, -Mike
I've fooled around with this and I'm still lost on how to get this idle squared away. I can get it close but it still just doesn't seem right. Either it idles fine when in gear and not so fine when out of gear or vice versa. Makes me want to get a six speed! I think my problem is I don''t know the range the counts should be at and I've tried a bunch of settings. Is it 32 at idle? If so is this at the desired idle rpm? How do you set that, with the tps disconnected? Can the counts at idle be in a prefered range? If so what is that range?
If anyone has a procedure on how they get their A4 car to idle correctly in Park and then when you put it in gear they still have a decent idle I sure would like to hear it. Thanks, -Mike
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Proceedure for setting mechanical stops for the TB is pretty much the same for the OBD 1 & 2. TPS should remain connected at all times. Consult your tuner to see what "step" count they would like to see at idle for your tune.
Typically:
IAC counts will change (decrease) as engine temps increases. Once the engine is up to normal operating temp for your application your target IAC step count should be in the neighborhood of 25 to 30 steps @ idle speed (in park/neutral) with very little fluxuation in either direction barring any RPM or temp increase. The way you alter this count is by adjusting your throttle stop screw. If your higher in steps then turn the TB throttle stop screw counter clockwise (slowly closing the blades) until your step target is achieved.
On older models with adjustable TPS sensors ensure that the voltage remains between .5 - .62 volts during and after proceedure.
Once set cycle the ignition "off" then restart engine. Check your results. The car should not bog or stall when placed into gear.
If poor idle quality remains this may be an indicator of other existing issues.
Typically:
IAC counts will change (decrease) as engine temps increases. Once the engine is up to normal operating temp for your application your target IAC step count should be in the neighborhood of 25 to 30 steps @ idle speed (in park/neutral) with very little fluxuation in either direction barring any RPM or temp increase. The way you alter this count is by adjusting your throttle stop screw. If your higher in steps then turn the TB throttle stop screw counter clockwise (slowly closing the blades) until your step target is achieved.
On older models with adjustable TPS sensors ensure that the voltage remains between .5 - .62 volts during and after proceedure.
Once set cycle the ignition "off" then restart engine. Check your results. The car should not bog or stall when placed into gear.
If poor idle quality remains this may be an indicator of other existing issues.
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
Proceedure for setting mechanical stops for the TB is pretty much the same for the OBD 1 & 2. TPS should remain connected at all times. Consult your tuner to see what "step" count they would like to see at idle for your tune.
Typically:
IAC counts will change (decrease) as engine temps increases. Once the engine is up to normal operating temp for your application your target IAC step count should be in the neighborhood of 25 to 30 steps @ idle speed (in park/neutral) with very little fluxuation in either direction barring any RPM or temp increase. The way you alter this count is by adjusting your throttle stop screw. If your higher in steps then turn the TB throttle stop screw counter clockwise (slowly closing the blades) until your step target is achieved.
On older models with adjustable TPS sensors ensure that the voltage remains between .5 - .62 volts during and after proceedure.
Once set cycle the ignition "off" then restart engine. Check your results. The car should not bog or stall when placed into gear.
If poor idle quality remains this may be an indicator of other existing issues.
Typically:
IAC counts will change (decrease) as engine temps increases. Once the engine is up to normal operating temp for your application your target IAC step count should be in the neighborhood of 25 to 30 steps @ idle speed (in park/neutral) with very little fluxuation in either direction barring any RPM or temp increase. The way you alter this count is by adjusting your throttle stop screw. If your higher in steps then turn the TB throttle stop screw counter clockwise (slowly closing the blades) until your step target is achieved.
On older models with adjustable TPS sensors ensure that the voltage remains between .5 - .62 volts during and after proceedure.
Once set cycle the ignition "off" then restart engine. Check your results. The car should not bog or stall when placed into gear.
If poor idle quality remains this may be an indicator of other existing issues.
So now I'm totally confused. I'm looking into the Park Neutral Safety switch as a possible cause for it not adjusting the idle when put into gear. It's like the PCM isn't getting the correct info to set the rpm correctly when it is put into gear. This isn't something that started with the addition of the cam and heads. It's always had idle issues.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
Thanks! That's pretty much how I've been going about it. Tuner said if it was as high a 60 counts it would be fine. So now I'm totally confused. I'm looking into the Park Neutral Safety switch as a possible cause for it not adjusting the idle when put into gear. It's like the PCM isn't getting the correct info to set the rpm correctly when it is put into gear. This isn't something that started with the addition of the cam and heads. It's always had idle issues.
So now I'm totally confused. I'm looking into the Park Neutral Safety switch as a possible cause for it not adjusting the idle when put into gear. It's like the PCM isn't getting the correct info to set the rpm correctly when it is put into gear. This isn't something that started with the addition of the cam and heads. It's always had idle issues.
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
It does Jim but it's like the PCM isn't adjusting for it when it's put into gear, no matter which gear. I have another PCM coming and should be here this week. I'm hoping that may fix some of these problems I'm having. The fans have gone nuts on me cutting on and off at temps they're not supposed to cut on and off at according to the settings in the tune. If if doesn't fix some of these things I'll have a spare one.
I can get these counts just right and the car idles pretty good. Cut the ignition off and reset the IAC and it goes back to where I last had it set. If I go for a drive and come back and check it it's all messed up again. I can sit there with it in drive and the counts just keep climbing to well over 100.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
If it were me:
I'd check the TB to see if it is returning to the stop screw (fully closed)every time you get off the throttle to rule out a mechanical issues with the TB.
Check for vacuum leaks when engine is cold/hot.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
It does Jim but it's like the PCM isn't adjusting for it when it's put into gear, no matter which gear. I have another PCM coming and should be here this week. I'm hoping that may fix some of these problems I'm having. The fans have gone nuts on me cutting on and off at temps they're not supposed to cut on and off at according to the settings in the tune. If if doesn't fix some of these things I'll have a spare one.
I can get these counts just right and the car idles pretty good. Cut the ignition off and reset the IAC and it goes back to where I last had it set. If I go for a drive and come back and check it it's all messed up again. I can sit there with it in drive and the counts just keep climbing to well over 100.
I can get these counts just right and the car idles pretty good. Cut the ignition off and reset the IAC and it goes back to where I last had it set. If I go for a drive and come back and check it it's all messed up again. I can sit there with it in drive and the counts just keep climbing to well over 100.
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Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
I have mine tuned and it has a different idle that the ECM commands. I shut off ALL the accessories and keep the engine running. This must be done in closed loop. I then hook up the scanner and set the min idle screw in or out depending on what I need. If the IAC count is high, screw it in. IAC count is low, screw it out. Reason is that a high IAC count means the ECM needs more air and the reverse it true.
Question. When you set it, is everything else, AC, lights, etc, etc off? Also when you set it, do you just set and forget? I adjust the screw, rev the engine up and see where it settles and then make adjustments till it is about 15-20 counts give or take. I have found that you need to rev it up to have it reset back and see where it settles at before you make the next adjustment.
Question. When you set it, is everything else, AC, lights, etc, etc off? Also when you set it, do you just set and forget? I adjust the screw, rev the engine up and see where it settles and then make adjustments till it is about 15-20 counts give or take. I have found that you need to rev it up to have it reset back and see where it settles at before you make the next adjustment.
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
I have mine tuned and it has a different idle that the ECM commands. I shut off ALL the accessories and keep the engine running. This must be done in closed loop. I then hook up the scanner and set the min idle screw in or out depending on what I need. If the IAC count is high, screw it in. IAC count is low, screw it out. Reason is that a high IAC count means the ECM needs more air and the reverse it true.
Question. When you set it, is everything else, AC, lights, etc, etc off? Also when you set it, do you just set and forget? I adjust the screw, rev the engine up and see where it settles and then make adjustments till it is about 15-20 counts give or take. I have found that you need to rev it up to have it reset back and see where it settles at before you make the next adjustment.
Question. When you set it, is everything else, AC, lights, etc, etc off? Also when you set it, do you just set and forget? I adjust the screw, rev the engine up and see where it settles and then make adjustments till it is about 15-20 counts give or take. I have found that you need to rev it up to have it reset back and see where it settles at before you make the next adjustment.
Nothing on except both the fans come on at 188 which isn't right. In looking at the tune their not supposed to come on until 195 or so. That does seem to change it some though. I guess because of the voltage drop.
I've messed with it some more and it seems to like 40 counts give or take at idle. Still not as good as I think it should be but it's much better. The damn thing is so sensitive, it's unreal how little you have to turn the screw to change the counts.
Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
no, I keep messing with either by revving the engine or turning the key off then waiting a few seconds and then crank it back up to see if it stays put. The FSM says it is reset each time the car is restarted.
Nothing on except both the fans come on at 188 which isn't right. In looking at the tune their not supposed to come on until 195 or so. That does seem to change it some though. I guess because of the voltage drop.
I've messed with it some more and it seems to like 40 counts give or take at idle. Still not as good as I think it should be but it's much better. The damn thing is so sensitive, it's unreal how little you have to turn the screw to change the counts.
Nothing on except both the fans come on at 188 which isn't right. In looking at the tune their not supposed to come on until 195 or so. That does seem to change it some though. I guess because of the voltage drop.
I've messed with it some more and it seems to like 40 counts give or take at idle. Still not as good as I think it should be but it's much better. The damn thing is so sensitive, it's unreal how little you have to turn the screw to change the counts.
