Not Turbo Specific, But Maybe Better In Here
09-05-2005, 02:57 PM
#1
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Hey i was experimenting with the ride today.. found out its not seized.. what a relief.. anyway.. i started her up.. and its idling high obviously since, i think my ISA is bad and the TB it propped open to stay alive.. well i was letting it sit and idle, and i turned off my AC, thus turning off the AC fan. then it idled a lil rough, and went from fine idle to leaner, lower idle, back and forth.. how could turning this fan off cause this?? i know that it would be warmer because one less fan cooling radiator but why would it be doing this.. with it on, it idles high yet fine.. and obviously doesnt like to drive, cuz the TB is permanently opened and the ISA isnt taking over for the idle..
anyone who can shed there expertise would be appreciated..
anyone who can shed there expertise would be appreciated..
09-09-2005, 10:56 AM
#2
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well it sounds like you just need to adjust the idle without the ac on, maybe i'm missing something but when you turn on the ac it should kick up the idle to accomodate for the extra load. so therefore create a little bit better idle.
btw whats the isa? it makes me thing idustry standard architecture.... (it's a pc slot like pci, agp, etc.) I'm guessing it has something to do with the idle air bypass valve??
btw whats the isa? it makes me thing idustry standard architecture.... (it's a pc slot like pci, agp, etc.) I'm guessing it has something to do with the idle air bypass valve??
09-09-2005, 11:04 AM
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^Idle Speed Actuator.
The ECU has a target idle speed for both "AC off" and "AC on", and obviously the AC on speed is greater. When you turned the AC off, the target speed went down, and it was too low to get the engine running good, so the ECU tried to compensate for it for a short time, then tried to use the specified speed again, thus creating the up/down idle speed loop.
The ECU has a target idle speed for both "AC off" and "AC on", and obviously the AC on speed is greater. When you turned the AC off, the target speed went down, and it was too low to get the engine running good, so the ECU tried to compensate for it for a short time, then tried to use the specified speed again, thus creating the up/down idle speed loop.
09-09-2005, 11:50 AM
#6
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yes, i just have the AC fan, but not the AC itself.. or AC components. when i turn the A/c button on, the fan turns on, and the idle goes up and stays steady.
thanks agarwal for your input, so would you think id need the new ISA installed, or do you think that this could be a MAF input error, say if i had my MAF voltages too high at certain rpm, etc.
so, maybe when i was adjusting the idle through the screw, which i shouldnt have to do with the idle speed actuator right; i should do it with the A/C (ac fan) off, so that when i turn it on, the idle will go lil higher when fan turns on, and when its turned off, it wont go into that dreaded loop.
thanks agarwal for your input, so would you think id need the new ISA installed, or do you think that this could be a MAF input error, say if i had my MAF voltages too high at certain rpm, etc.
so, maybe when i was adjusting the idle through the screw, which i shouldnt have to do with the idle speed actuator right; i should do it with the A/C (ac fan) off, so that when i turn it on, the idle will go lil higher when fan turns on, and when its turned off, it wont go into that dreaded loop.
09-13-2005, 10:03 PM
#7
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you wouldnt need an new ISA, just redo your settings with the ac fan off.
ur using an emanage, right?
i am not familiar with those, but either way, you shouldnt have to buy a new isa.
ur using an emanage, right?
i am not familiar with those, but either way, you shouldnt have to buy a new isa.
