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Installed Ported TB now idle issue

Old Apr 23, 2007 | 08:09 PM
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Default Installed Ported TB now idle issue

So i just installed my performance throttle bodies throttle body. Everything feels fine driving around but now when my car comes back to idle it sits around 1500rpms for awhile until I come to a complete stop. Once I stop it drops down to normal idle.

Any ideas?
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Old Apr 23, 2007 | 08:43 PM
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It's re-learning. It will go to normal idle after few more miles.
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Old Apr 23, 2007 | 09:00 PM
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Thanks I'll drive it to work tomorrow and see how she does.
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Old Apr 23, 2007 | 09:02 PM
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Mine did the exact same ****, and sometimes still does, but not 1500RPM... how long does it take to re learn?

-J
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Old Apr 23, 2007 | 09:06 PM
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.....mine did the same thing then I saw that I forgot to put the orange o-ring back in my IAT sensor, easy to miss now it idles fine!
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Old Apr 23, 2007 | 09:08 PM
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Originally Posted by MasnarT
.....mine did the same thing then I saw that I forgot to put the orange o-ring back in my IAT sensor, easy to miss now it idles fine!
The IAT is on the MAF right? I didnt take that off when I changed the TB.
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Old Apr 23, 2007 | 09:09 PM
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When I did mine I let the car run for 15 min and then turned on the AC and let it run for another 10. After that I adjusted my idle screw and havnt had an issue since.
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Old Apr 23, 2007 | 09:09 PM
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Originally Posted by MasnarT
.....mine did the same thing then I saw that I forgot to put the orange o-ring back in my IAT sensor, easy to miss now it idles fine!
The IAT sensor is before the maf so why did that cause a issue?
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Old Apr 23, 2007 | 11:54 PM
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.....sorry wrong term, it was the IAC valve above the TPS on the throttle body,
you can also try to pull the IAC/TPS pigtail off and turn the key to ON for a couple and then turn the key to OFF and plug them back on, I read this sometimes works to...........sorry for the mix up
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Old Apr 24, 2007 | 12:15 AM
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Same here. I havent caught what Im doin to make it do it now and then, but it doesnt seem to be anything serious.

Originally Posted by lastcall190
Mine did the exact same ****, and sometimes still does, but not 1500RPM... how long does it take to re learn?

-J
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Old Apr 24, 2007 | 02:35 AM
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had mine on for over a month and a lot of miles...still does it..~1100rpm is about what it sticks at until i stop
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Old Apr 24, 2007 | 09:18 AM
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2 things to check.... make sure all four plugs in that area are secure... and also check the diameter of the hole drilled in the throttle plate... wherever you got it from may have had it drilled larger.. which is the cheater way of raising idle for a cam. mine was that way... had to replace it with my stocker.
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Old Apr 24, 2007 | 11:44 AM
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Well this is something that seems to be common with only 6 speed cars. I am assuming everyone that posted is a 6 speed and since it idles normal when the car is at rest, it seems like the iac sensors are letting to much air by when the clutch is pushed in/ car is in neutral. I have read that this is pretty common among 6 speed cars and have read that by unplugging the tps and iac connections, turning the key off and on a couple times, then driving it for 30 minutes usually works. Some people have to have their tunes adjusted as well. Make sure the orange o-ring is under the iac sensor and is in the right slot, as this will cause a vacuum leak as well. Other than that its pretty normal to sit higher and then come down as the car comes to a stop. If anyones is idling at 1000 or greater for a stock car at idle then there is something else wrong.
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Old Apr 24, 2007 | 02:24 PM
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It seeme dlike it was calming down on the way to work this morning. I am heading hom ein abou t30 minutes (about a 25 minute commute) so I'll let you know how it goes. If its not better I'll try disconnecting the TPS and IAC trick and see how that goes.
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Old Apr 24, 2007 | 04:08 PM
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Try taking the throttle shaft and throttle plate out of your stock one and swapping it back into the ported one. I have an auto and that's what I had to do. My idle was at about 750 after installing the ported one and it should be 550. After swapping that I got it down to 600. I think if you grind down that throttle shaft too close to the housing a bunch of air comes around the plate through that void created there. I also have some imperfections in my housing where it was ground a little too far and the throttle plate does not sit completely flush to the housing, that's probably my extra 500 rpm's. I'd bet anything that will fix your problem. At idle, if done right, you shouldn't have to adjust anything on your car when installing a PTB because it shouldn't affect the air coming in when the plate is completely closed at idle.

Last edited by Spink; Apr 24, 2007 at 06:26 PM.
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Old Apr 24, 2007 | 04:25 PM
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WEll i just drove it around for a bit. its still doing it . it is stopping around 1200 or so rpms I guess. I pulled the TPS and IAC plugs and turned the key on and off and then drove it for a bit with no results.

The rpms also shoot up brieflly to about 1000 rpms when i cut on the A/C . Its about to rain here but I think I am gonna pull the whole thing off and reinstall tomorrow afternoon. It drives fine but I'm hesitant to go WOT in case there is extra un-metered air getting in.

I also pulled the sensors and checked the o-rings. Everything looked fine and fit nice and snug.
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Old Apr 25, 2007 | 02:36 AM
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Originally Posted by MasnarT
.....sorry wrong term, it was the IAC valve above the TPS on the throttle body,
you can also try to pull the IAC/TPS pigtail off and turn the key to ON for a couple and then turn the key to OFF and plug them back on, I read this sometimes works to...........sorry for the mix up
That speeds up the relearn, if this doesnt do it the you may have a sticky IAC or a vacuum leak. Vacuum leaks are a possibilty, if air is entering the engine by other paths than the MAF then the computer wigs out lol. Your TPS can do it too, if the sensor is getting old it may send a faulty reading to the computer that the blade hasnt closed all the way.
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Old Apr 25, 2007 | 07:26 PM
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It would better if people posted their IAC counts. Very low IAC counts indicate too much air getting by. It could simply be that you need to adjust the idle set screw. Close it a full turn and see if that helps.
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Old Apr 25, 2007 | 08:02 PM
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Well i drove it to work again today and it wasnt any better.

However one the commute home it was PERFECT. The idle didnt hang once in my 25 minute trip home. I guess it was just the computer relearning as was mentioned. Thanks for all your help guys. If it comes back I'll let you know.
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Old Apr 25, 2007 | 08:03 PM
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I am still having problems with mine also since porting. What will read IAC counts? I have nothing to read it and would have to have someone to do it.
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