IAC problem?
07-08-2005, 11:15 PM
#1
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IAC problem?
I have a 99 GT with a VT Sportsman motor, VT Stage II cams and most of the bolt ons. My car is tuned by Steeda.ca with a SCT chip.
The car ran perfectly when I got it back, but then a problem started a few weeks later.
The car starts fine for the most part but when depressing the clutch and coming to a stop in neutral the car stalls. Not all the time, just sometimes. The idle tends to hunt a lot more too.
Other times, the car runs great. Not even a hiccup.
Sometimes, the car doesn't like to start very well. It takes 10+ seconds to get it started.
Is this an IAC problem?
The car ran perfectly when I got it back, but then a problem started a few weeks later.
The car starts fine for the most part but when depressing the clutch and coming to a stop in neutral the car stalls. Not all the time, just sometimes. The idle tends to hunt a lot more too.
Other times, the car runs great. Not even a hiccup.
Sometimes, the car doesn't like to start very well. It takes 10+ seconds to get it started.
Is this an IAC problem?
07-09-2005, 12:23 AM
#2
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The IAC may be the stalling issue but I doubt it's connected to poor starting. I would start off by cleaning your cable connections both at the battery and at the engine, the way top terminal batteries cause corrosion your always best to clean em pretty regularly. If that checks out ok you might wanna have Paul run it while hooked to the scanner to confirm all sensors are working properly.
I will however ad that several folks report periodic poor starting with 4.6's. Yesterday when Raf was over his car required 2 or 3 goes at the key to bring it to life, he said it's an off and on problem.............mine isn't as bad as that but does require a second turn of the key at times.
I will however ad that several folks report periodic poor starting with 4.6's. Yesterday when Raf was over his car required 2 or 3 goes at the key to bring it to life, he said it's an off and on problem.............mine isn't as bad as that but does require a second turn of the key at times.
07-09-2005, 12:52 AM
#3
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Originally Posted by ZR 5.0
The IAC may be the stalling issue but I doubt it's connected to poor starting. I would start off by cleaning your cable connections both at the battery and at the engine, the way top terminal batteries cause corrosion your always best to clean em pretty regularly. If that checks out ok you might wanna have Paul run it while hooked to the scanner to confirm all sensors are working properly.
I will however ad that several folks report periodic poor starting with 4.6's. Yesterday when Raf was over his car required 2 or 3 goes at the key to bring it to life, he said it's an off and on problem.............mine isn't as bad as that but does require a second turn of the key at times.
I will however ad that several folks report periodic poor starting with 4.6's. Yesterday when Raf was over his car required 2 or 3 goes at the key to bring it to life, he said it's an off and on problem.............mine isn't as bad as that but does require a second turn of the key at times.
07-09-2005, 01:13 AM
#4
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Originally Posted by CMOC Admin
Paul's been all over this car and tuned it a couple times. I will check the terminals over the week-end. Thanks
07-09-2005, 03:15 PM
#5
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Sounds like the maf transfer function could be rich in the lower end of the curve... It could be learning the wrong correction as well, due to an o2 sensor problem or a exhuast leak.
Another area of the program to look at is the dashpot settings.
All the above must be changed in the program/tuner.
Disconnect the battery and wait a couple minutes to clear the KAM. If the issue goes away, but comes back after a couple weeks, its definately a tune/sensor related issue.
.02
Matt
Another area of the program to look at is the dashpot settings.
All the above must be changed in the program/tuner.
Disconnect the battery and wait a couple minutes to clear the KAM. If the issue goes away, but comes back after a couple weeks, its definately a tune/sensor related issue.
.02
Matt
07-09-2005, 03:45 PM
#6
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Originally Posted by THREE40SEVEN
Sounds like the maf transfer function could be rich in the lower end of the curve... It could be learning the wrong correction as well, due to an o2 sensor problem or a exhuast leak.
Another area of the program to look at is the dashpot settings.
All the above must be changed in the program/tuner.
Disconnect the battery and wait a couple minutes to clear the KAM. If the issue goes away, but comes back after a couple weeks, its definately a tune/sensor related issue.
.02
Matt
Another area of the program to look at is the dashpot settings.
All the above must be changed in the program/tuner.
Disconnect the battery and wait a couple minutes to clear the KAM. If the issue goes away, but comes back after a couple weeks, its definately a tune/sensor related issue.
.02
Matt
Paul from Steeda.ca recommended I change my O2's. I was just hoping that perhaps it was a cheaper fix than $200 pair of sensors
07-11-2005, 12:48 AM
#7
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Tonight I took the IAC off. Would a mis-aligned gasket cause this? The gasket was covering at least 1/3 of the hole.
I cleaned the IAC and aligned the gasget properly and put the IAC back on. I disconnected the battery and will fire it up tomorrow and see if any of that made a difference.
I cleaned the IAC and aligned the gasget properly and put the IAC back on. I disconnected the battery and will fire it up tomorrow and see if any of that made a difference.
07-11-2005, 06:57 AM
#8
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Originally Posted by CMOC Admin
Tonight I took the IAC off. Would a mis-aligned gasket cause this? The gasket was covering at least 1/3 of the hole.
I cleaned the IAC and aligned the gasget properly and put the IAC back on. I disconnected the battery and will fire it up tomorrow and see if any of that made a difference.
I cleaned the IAC and aligned the gasget properly and put the IAC back on. I disconnected the battery and will fire it up tomorrow and see if any of that made a difference.
More than possible, you'll know better tomorrow after driving it for a bit.
Fingers crossed for you.
07-11-2005, 10:13 PM
#9
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Originally Posted by ZR 5.0
More than possible, you'll know better tomorrow after driving it for a bit.
Fingers crossed for you.
Fingers crossed for you.
07-11-2005, 11:26 PM
#10
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Originally Posted by CMOC Admin
Well, the culprit was the IAC. She runs just fine, doesn't hunt one bit and idles right about 1k. Now I can get back to enjoying the car ::biggrin:
Gotta get lucky sometimes............
