Ilde problem
09-12-2006, 12:21 PM
#1
Ilde problem (probably new to YOU) I have had a heck of a time with my idle lately.
I am running a olsd tune right now. Sometimes the car will not stay running unless my foot is on the gas. I scanned my car and noticed something. On a cold start my IAC counts start out pretty high and taper down to around 30 which is normal. I let it idle there for a few minutes and it held idle as good as stock. I reved the car up a few times and then when it settled down my IAC counts and my Desired IAC drop to less than 5 and then somtimes to 0 and stay there. With the IAC at 0 the car will not idle up to the rpm that I have it set at which is 1000 right now.
I was at the track the other night and when I started the car hot it would not stay running with my foot off the gas and the IAC was at 0. Im wondering what kind of condition would make the computer think that it needs to close the IAC completely. If the desired IAC was one number and the actual IAC was another then I would say the IAC is bad but I checked it using the VCM controls and it moved.
I am running a olsd tune right now. Sometimes the car will not stay running unless my foot is on the gas. I scanned my car and noticed something. On a cold start my IAC counts start out pretty high and taper down to around 30 which is normal. I let it idle there for a few minutes and it held idle as good as stock. I reved the car up a few times and then when it settled down my IAC counts and my Desired IAC drop to less than 5 and then somtimes to 0 and stay there. With the IAC at 0 the car will not idle up to the rpm that I have it set at which is 1000 right now.
I was at the track the other night and when I started the car hot it would not stay running with my foot off the gas and the IAC was at 0. Im wondering what kind of condition would make the computer think that it needs to close the IAC completely. If the desired IAC was one number and the actual IAC was another then I would say the IAC is bad but I checked it using the VCM controls and it moved.
Last edited by Full-Force; 09-12-2006 at 09:03 PM.
09-12-2006, 12:52 PM
#2
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What do your idle trims look like? Not fuel trims, but airflow trims... If your Base Running Airflow (Desired Airflow in EFILive) is too low, it will try to close off the extra airflow. See the following thread for more info...
https://ls1tech.com/forums/showthrea...hlight=desired
https://ls1tech.com/forums/showthrea...hlight=desired
09-12-2006, 05:36 PM
#4
ok here is an update
I have a P0122 TPS low voltage code and I have a P0336 crankshaft position sensor code.
My car would not stay running at the track the other night. Well today I logged it and found out a few things. My IAC desired and my actual IAC steps will hoover around 30 once the engine settles down. Once I give it gas they both fall to 0 and never move again. If the car starts to die they never go up in an effort to regain idle.
Also I have my idle set to 1000. As long as I dont touch the gas it will idle at 1000. Once I hit the gas to rev it up and let it settle back down, not only will my IAC fall to 0 but the car will never reach 1000rpms again. Even when the idle does smooth back out it will only idle about 700-800 rpm's.
Bck to my TPS. I have reset it time and time again but italways reverts back to 2% after a few minutes. If I reset it I can get it back to 0% until I hit the gas and then it will only go back to 2%.
My instinct is to go out and buy a TPS and Crank sensor but those will be well over 100 bucks and come with no return since its electrical.
I have a P0122 TPS low voltage code and I have a P0336 crankshaft position sensor code.
My car would not stay running at the track the other night. Well today I logged it and found out a few things. My IAC desired and my actual IAC steps will hoover around 30 once the engine settles down. Once I give it gas they both fall to 0 and never move again. If the car starts to die they never go up in an effort to regain idle.
Also I have my idle set to 1000. As long as I dont touch the gas it will idle at 1000. Once I hit the gas to rev it up and let it settle back down, not only will my IAC fall to 0 but the car will never reach 1000rpms again. Even when the idle does smooth back out it will only idle about 700-800 rpm's.
Bck to my TPS. I have reset it time and time again but italways reverts back to 2% after a few minutes. If I reset it I can get it back to 0% until I hit the gas and then it will only go back to 2%.
My instinct is to go out and buy a TPS and Crank sensor but those will be well over 100 bucks and come with no return since its electrical.
09-12-2006, 07:55 PM
#5
Another update.
Out of frustration I copied my stock VE table from 400-1200 over my current tune to start over. It was pig rich and would not idle at all. It was around 12:1. I leaned it out by 10% 3 or 4 times, cant remember now. Now its idling at 14.7:1 give or take a little.
Start the car and it idles good. Pat the gas a few times to rev up and trhen when it settles down the desired iac and the iac counts fall to 0 and stay there. Atleast now the car still runs when this happens.
Out of frustration I copied my stock VE table from 400-1200 over my current tune to start over. It was pig rich and would not idle at all. It was around 12:1. I leaned it out by 10% 3 or 4 times, cant remember now. Now its idling at 14.7:1 give or take a little.
Start the car and it idles good. Pat the gas a few times to rev up and trhen when it settles down the desired iac and the iac counts fall to 0 and stay there. Atleast now the car still runs when this happens.
09-13-2006, 12:45 PM
#7
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1) Did you by any chance just use the tb set screw to dial in idle? To get the TP% back in line, you may have to drill the tb a little and close the set screw some. You need to fix this first because (if I recall correctly) the PCM will consider itself to be in non-idle mode with any TP% greater than 0. That's most likely why your IAC counts aren't responding.
2) Have you logged your RAFIG or RAFPN when the IAC is working? If not, you have no idea if the PCM thinks it's getting enough air or not. You need to know this in order to dial in the Base Running Airflow (Desired Airflow if EFI Live) table.
3) As for the IAC, what has been done to the airflow tables that affect the IAC's movement in the tune? Anything?
2) Have you logged your RAFIG or RAFPN when the IAC is working? If not, you have no idea if the PCM thinks it's getting enough air or not. You need to know this in order to dial in the Base Running Airflow (Desired Airflow if EFI Live) table.
3) As for the IAC, what has been done to the airflow tables that affect the IAC's movement in the tune? Anything?
