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Ported TPI throttle body

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Old 09-12-2017, 06:59 PM   #1
chrisdefo
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Default Ported TPI throttle body high idle

Hey guys so I just recently ported my stock tpi throttle body. Ive done a few before (not TPI) but was a little weary about the IAC on this one So i did a mild port job and did not go near the butterfly valves, well I got close but no I did not get close enough to take material away opening the gap more at the butterfly valves. When I started the car it idled fine, cruised down my street under 25mph fine. When I got back the car seemed to idle higher and once I put it into park the revs jumped and sat around 1400rpm (using an accurate tach). I shut the car down and let it sit about 15 minutes then started it back up. Car idled fine until I got out of my neighborhood and to the first light, it started to rev higher and higher until it hit about 1400rpm again and sat there. If I turn the AC on the rpms drop to about 950-1000rpm, also if I turn the car on once it has been sitting it will fire up and idle fine all day long. I pulled the IAC and made sure everything was clean and no metal shavings snuck in. I replaced throttle body gasket, and the top manifold/runners gasket. Could not find any leaks and also checked to make sure all sensors and vaccum lines are hooked up. No engine light either.

Last edited by chrisdefo; 09-12-2017 at 07:27 PM.
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Old 09-13-2017, 05:26 PM   #2
aklim
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Why exactly did you port it? What problem were you trying to solve?

Did you set the IAC to run with that new ported thing? IDK how to do that now but I suspect you confused it since it was expecting a certain amount of air when opened to whatever the TPS setting was and now it got more and is trying to compensate. So once again, why did you port this thing? You may have made it FUBAR.
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Old 09-13-2017, 05:27 PM   #3
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You might try resetting the IAC using the IAC counts but if that can't fix it, you might have to get a new TB.
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Old 09-13-2017, 08:25 PM   #4
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Everything is all good 👍🏼. One of the pins to the connector was pushed out and bouncing on the contact point. I ported it because me and a friend are installing a gt357r turbo and feel a ported tpi throttle body will work sufficiently for our power goals. I thought it has something to do with minimum idle but wasn't sure about the procedure with 91 tpi and it being computer controlled.
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