Ported Throttle Body Issue
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From: Derby Line, VT
Ported Throttle Body Issue I bought a ported throttle body for one of the two LS1 conversions I was going to do, last year. Got it, but never got around to installing it, just sat in the box. Sold it last week, and just got a message from the guy who bought it from me:
Anybody got any suggestions?
Hello there .....
I got the throttle body a couple of days ago ..... Just put it in today but I have a problem ...... It went in like a champ and everything seemed fine ..... but when I started the car the car just sits there and revs between 1000 and 2000 rpms and if you rev the motor to like 4000 it takes like 4 or 5 seconds for it to go back down to idle ......
But the stock was put back on and no problems ..... I do not know if you go any solutions to this or what.
I got the throttle body a couple of days ago ..... Just put it in today but I have a problem ...... It went in like a champ and everything seemed fine ..... but when I started the car the car just sits there and revs between 1000 and 2000 rpms and if you rev the motor to like 4000 it takes like 4 or 5 seconds for it to go back down to idle ......
But the stock was put back on and no problems ..... I do not know if you go any solutions to this or what.
maybe reset the pcm and go through a couple of drive cycles and see if it can learn the new incoming airflow. just my opinion.
Last edited by Wickid Z; Feb 20, 2005 at 12:39 AM.
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From: Live Oak, FL - in the woods where the creatures lurk.
If the air inlet to the IAC was filled/redrilled it may be that the IAC plunger is sticking. Could be something got between the plunger and the seat. Mine did this when I first cranked it after reinstalling the TB , but the stepper motor made a hell of a racket then finally broke loose. From there I just did the idle relearn procedure. Also check the O ring for the IAC.
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From: NC, Charlotte / SC, RockHill
Looks like that u guys ported the hole in the throttlebody more than it should be . This one way to raise the idle sometimes.... I did that when i installed my cam untill I get my hptuners..
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Is his car a '98-99? And what year motor was the throttle body from? If his car was a '98 or '99 and he put a 2000+ throttle body on the car his throttle cable will be to short cracking the throttle body open when it should be closed. The 98-99 bodies use a smaller cam on the end then the 2000+ throttle bodies use.
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Yeah, I've seen lots of problems when you switch years of tb's. Either the cam is too big and the throttle won't go down to idel, or it won't hit WOT, etc. If it is a dif year tb, you at least need to pull the mechanical parts (cam etc) from correct model year and use it.
after you check to make sure the years for the tb match up for the application, and have messed with the idle screw, forget the PCM. the tb's are VERY tempermental when you tighten the screws that hold the blade on the shaft. take the tb off the car, and loosen the screws, then swing the throttle cam open and closed a couple times. slowly tighten the screws while doing this, every couple rotations swing the throttle cam to ensure it keeps opening and closing freely. once your done, you should be able to open the throttle cam all the way, and then let go and it should close w/only the final snap when the throttle stop hits the housing, no sounds of brushing or anything. hope this helps!!
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From: Austin, TX by way of Chicago, IL
There's a bigger than stock hole in the throttle body blade. I installed a Bauer racing TB last weekend and mine idles around 950-1000 rpm. It also takes time to settle down after a rev. No big deal in my opinion.
How would one go about doing the PCM relearn and also the idle relearn when they install a ported throttle body on their car.
This should stop the slight revving it does right now when I install it and also get rid of the cruise control effect when I let off the gas ..... right?
If not what can I do about it ...... It is of the same year vehicle and the hole in the blade is the same size as the one in my factory blade ...... I used a micrometer to check it.
This should stop the slight revving it does right now when I install it and also get rid of the cruise control effect when I let off the gas ..... right?
If not what can I do about it ...... It is of the same year vehicle and the hole in the blade is the same size as the one in my factory blade ...... I used a micrometer to check it.
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Originally Posted by Neolloyo
How would one go about doing the PCM relearn and also the idle relearn when they install a ported throttle body on their car.
This should stop the slight revving it does right now when I install it and also get rid of the cruise control effect when I let off the gas ..... right?
If not what can I do about it ...... It is of the same year vehicle and the hole in the blade is the same size as the one in my factory blade ...... I used a micrometer to check it.
This should stop the slight revving it does right now when I install it and also get rid of the cruise control effect when I let off the gas ..... right?
If not what can I do about it ...... It is of the same year vehicle and the hole in the blade is the same size as the one in my factory blade ...... I used a micrometer to check it.
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From: Omaha
What he said... If that doesnt fix it then the TB is just slightly over ported around the blade area and can be fixed with some minor tuning.
Originally Posted by cyphur_traq
after you check to make sure the years for the tb match up for the application, and have messed with the idle screw, forget the PCM. the tb's are VERY tempermental when you tighten the screws that hold the blade on the shaft. take the tb off the car, and loosen the screws, then swing the throttle cam open and closed a couple times. slowly tighten the screws while doing this, every couple rotations swing the throttle cam to ensure it keeps opening and closing freely. once your done, you should be able to open the throttle cam all the way, and then let go and it should close w/only the final snap when the throttle stop hits the housing, no sounds of brushing or anything. hope this helps!!
