Need help with ls2 408 in a 2000 firebird

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May 23, 2007 | 04:41 PM

BLACKSS02

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Need help with ls2 408 in a 2000 firebird

Hello everyone i need some help with this car its a ls2 408 vortec t trim supercharged deal i got it tuned and the car runs hard when you are on it but it idles like crap and when we hook it up to a scaner it shows no iac counts and it will rev to like 5000 rpm can anyone please help me with this thanks

May 24, 2007 | 11:02 AM

BLACKSS02

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can any buddy help me please or tell me who can help me thanks

May 24, 2007 | 11:17 AM

SMOKINV8

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Finding a local tuner is your best option.

That being said, it sounds to me like you either have a throttle cable issue, or a huge vacuum leak.

May 24, 2007 | 11:30 AM

Frost

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cable issue should show up as + TPS though, so the IAC would likely be open.... I'd go with vacuum leak (or leaky TB blade, etc)or a tune thats WAAAAAYYY off down low.

May 24, 2007 | 02:45 PM

BLACKSS02

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has anyone had any problems with fast intakes leaking or something like that

May 24, 2007 | 03:36 PM

My90Iroc

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Quote:

Originally Posted by BLACKSS02

has anyone had any problems with fast intakes leaking or something like that

More than you'd probably like to hear. The fact that you said it revs to 5k probably means intake leak. If it were only reving to 1500 I'd say it's in the tune. If you have a fast intake then you probably have a throttle body with an adjustment on it. You could try to close the throttle blade a little through the adjustment screw to see if that helps any. That should bring iac counts up as you close the blade. See how it acts then.

Check the back (pass. side) of the manifold and make sure the vacuum line in on all the way. You can also reach back to the map sensor and make sure it's in all the way. Many times on the fast intake the map doesn't fit well.

You can also spray down the intake to check for leaks. Get something nonflamable like gum cutter or something and spray it on the areas that could leak like around the top shell, behind the throttle body, and if you can where the manifold meets the heads. If you spray a spot and the car bogs then that's where your leak is. Good luck.

May 24, 2007 | 11:50 PM

BLACKSS02

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thanks for the info. could the blower have anything to do with it reving to 5000 rpms sometimes or the bypass valve. Someone told me that my bypass valve was to small and i need to get the mondo bypass valve when you use the T-trim supercharger