LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Weird Idle

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Old Feb 23, 2013 | 09:12 PM
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RubberDucky21's Avatar
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Default Weird Idle

I have a 96 z28 M6 and when I first start it up the rpms jump from around 1500 all the way down to like 450 and almost stalls.
Also while cruising (45-60 mph) I feel the car kinda lurch a little. I've heard it could be a vacuum leak but I'm not sure. Any suggestions?
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Old Feb 24, 2013 | 01:14 PM
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any modifications on your car? knowing this makes it easier for people to help ya

is the ses light on?
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Old Feb 24, 2013 | 01:35 PM
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Any work done recently?

If you can't hear and obvious vacuum leak, you can spray some carb cleaner around and if it affects rpm then you have a leak somewhere.
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Old Feb 24, 2013 | 08:23 PM
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No recent mods but it does have CAI, ported intake manifold and TB, and 3 inch straight pipes. I'll try the cleaner when I get a chance
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Old Feb 24, 2013 | 08:28 PM
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Ported stock TB?
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Old Mar 5, 2013 | 03:00 AM
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the TB im not sure if it's stock or aftermarket. was on when i bought the car. i know the rpm jumps are from the vacuum leak which i know for sure i have. what problems could cause the lurching while im cruising? bad spark plugs/cylinder?
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Old Mar 11, 2013 | 10:46 PM
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ok the throttle body is aftermarket, guy is actually sending me the stock one. but the vacuum leak, once i find it, can i just find the same size rubber hose and pop it on?(like a hose from autozone) im pretty new to these things but ive heard that you can do this.
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Old Mar 15, 2013 | 05:25 PM
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Ok so the "leak" was from the CAI. The person who worked on it last when I replaced the water put out it on wrong. But my O2 sensors are most likely out. Anyone have experience with these?
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Old Mar 15, 2013 | 05:40 PM
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is your ses light on? how do you know your o2 sensors are bad?

removing o2's are a pain in the butt sometimes. soak them in wd-40 or pb blaster for a while before you try turning them out
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