Possible Vacuum Lines Missing???
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Joined: Oct 2017
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Possible Vacuum Lines Missing???
My 89 RS 305 TBI Has a Random Hissing Sound When the Car is Running Pop the Hood and U Hear it Hissing Cant Tell Where its Coming from but as the Car Warms Up and Drives It Goes Away After its Running you still Hear it Just not as Much when the Car is Warm and Idle Drops to about 900Rpm (Normal) But can Anyone give me Info Where to Start Looking And what to Becareful Of Thanks
Joined: Jun 2000
Posts: 5,364
Likes: 51
From: Enschede, Netherlands
Car: 82 TA 87 IZ L98 88 IZ LB9 88 IZ L98
Engine: 5.7TBI 5,7TPI 5.0TPI, 5,7TPI
Transmission: T5, 700R4, T5, 700R4
Axle/Gears: 3.08, 3.27, 3.45, 3.27
Re: Possible Vacuum Lines Missing???
Iac passage and cold higher iac position.
Joined: Jun 2000
Posts: 5,364
Likes: 51
From: Enschede, Netherlands
Car: 82 TA 87 IZ L98 88 IZ LB9 88 IZ L98
Engine: 5.7TBI 5,7TPI 5.0TPI, 5,7TPI
Transmission: T5, 700R4, T5, 700R4
Axle/Gears: 3.08, 3.27, 3.45, 3.27
Re: Possible Vacuum Lines Missing???
Idle air control
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From: Chasing Electrons
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Engine: check
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Re: Possible Vacuum Lines Missing???
Round thing protruding from the right hand side of the TBI unit. Has a square 4-wire connector on it. Note that the hissing is normal, with the stock air cleaner it can't be heard.
RBob.
RBob.
Joined: Dec 2004
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
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From: Michigan
Car: 86 IROC Z, 92 RS
Engine: 305 4bbl, 305 TBI
Re: Possible Vacuum Lines Missing???
I have the same hissing sound with my tbi since I've had an open element air cleaner. Sounds a little alarming, but it's ok, and it runs very well.