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What could be leaking?

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Old 08-18-2012, 09:51 PM   #1
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Default What could be leaking?

I recently put a ported throttle body on my car and when rolling down the highway if i push the clutch in and throw it in neutral the revs spike up. I recently put the stock throttle body back on and the issue remains. My tuner also said that the LTFTs have been allover the place and that the cars running lean
. Just curious where i should start looking for leaks? Thanks
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Old 08-18-2012, 10:53 PM   #2
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def going to be a vacum leak
use carb cleaner/brake clean, spray enigne down when running and listen for spike in rpm, that will help pin point the leak.
check the vacum lines, intake maniflod, anything post maf
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Old 08-18-2012, 11:57 PM   #3
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Doesn't brake clean drop the rpm?
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Old 08-19-2012, 12:23 AM   #4
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Starting fluid works real well

But there arn't many places on the V's for a vacuum leak. The vacuum hose to the brake booster, the hose from the valley cover, the plastic hose at the neck of the intake that runs to the back of the car, or on the back of the intake manifold there is a small nipple that has a plastic cap that break off sometimes next to where the break booster hose plugs in (you can just cap it), or there is a crack in the manifold somewhere.

That's about the only places where you can get a vacuum leak on the ls2 V's idk how different it is on the ls6's
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Old 08-19-2012, 01:22 AM   #5
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The starting fluid idea is a good one. I should have mentioned its an ls6 v. But im gonna get a can of ether to see. Another member on CF mentioned about 10 places to check so i guess ill just spray a bunch of ether on all those places. Thanks for all the input and ill keep you guys posted if i get it fixed or not..
Thanks again
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Old 08-19-2012, 01:39 AM   #6
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The problem with starting fluid is it makes narrowing down a smaller leak near impossible since there is so much fuel evaporation going on all at once. There is also a much larger chance of a marginal plug wire, alternator or the like lighting off the starting fluid compared to brake or carburetor cleaner.

If you don't find a leak there might be issues with the throttle position sensor, MAP, and mass air flow correlations. I am not by any means a tuner, so ask them first. I am just starting to lurk in the PCM tuning forum and have sooooo much to learn.

Good luck.

Last edited by Brian68; 08-19-2012 at 01:50 AM. Reason: Added information
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Old 08-19-2012, 09:19 AM   #7
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howanic, you're allowed to give me a call.

I sold him the throttle body, and I had no issues like this, whatsoever. I think you either have a cracked/leaking vacuum line, or a bad TB gasket.

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Old 08-19-2012, 07:09 PM   #8
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I just took it for a ride and it seems worse. I had my trinity plugged in and it looks like when i let off while rolling to a stop w/ the car in neutral the absolute throttle position goes up like 10-13% could this be my throttle position sensor going bad but not bad enough to throw a code? Also while i was driving it it went into reduced power mode and threw a code but i didnt catch it cuz i cleared it to get out of traffic. But i did see intake manifold something sensor bank 1 i believe
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bad, car, common, drive, leak, leaks, ls2, vacuum

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