FAST 102 Vacuum Leak problem
Thread Starter
Teching In
Joined: Oct 2010
Posts: 19
Likes: 0
From: Topeka, Kansas
I finally figured out my problem. It wasn't a vacuum leak afterall and my new found buddy from New Zealand was in the ball park on the PCV valve. I got to playing around and looking at another thread and noticed a guy put a breather on one of the tubes out of the passenger side valve cover. My 1997 has 2 tubes coming out ot the passenger side for the pcv system. I hooked them both up using a t connector for the front one. My car was sqealing like a hog stuck under a gate and I thought is was an intake leak. I disconnected one of the lines to one of the tubes out of the passenger side and all the noise stopped. I put a breather on this one and now everything is fine. No noise. Now I just need a tune. I am guessing the LS2 throttle body changed the intake vacuum enough to screw up the stock PCV air flow. It took me over a week to figue this thing out. Thanks for the ideas and help.
Thread Starter
Teching In
Joined: Oct 2010
Posts: 19
Likes: 0
From: Topeka, Kansas
Talked to Ragin Racin. They explained how the TB is not reacting the same because of the big difference in size from stock. I am taking it to a tuner to get it tweaked in. Thanks again for the advice. Maybe I can pay you back some day.
Thread Starter
Teching In
Joined: Oct 2010
Posts: 19
Likes: 0
From: Topeka, Kansas
After figuring out the PCV problem. It was really one fitting causing all the issue. The elbow off the driverside valve cover was getting hot and collapsing on itself. I replaced all the lines with Transmission coolant line and moved the PCV to just before the oil catch can. I just finished having it tuned in Kansas City. This thing is running great. Now I am really happy even though it was a pain to figure it out. Uped the rev limiter to 6800rpm. Sounds great you can really hear the air sucking into the motor.
TECH Fanatic
Joined: Aug 2004
Posts: 1,375
Likes: 5
From: Auckland, Nth Is, New Zealand.
Hey that's great, hopefully mine will be going by the end of the week. Mine uses a big pod filter, through that the sucking was loud,i was using a 78T/B & LS6 intake, can only imagine how much louder it will be through the 102/102
Interesting thread. I just installed a FAST intake on my 01 C5, I got a brand new 78mm model dirt cheap so I couldn't resist.
The intake itself is nice enough, but it is obvious that FAST tries way to hard to make their intake fit all models of LS equipped cars, resulting in individual fitment issues for each model. I cant believe for the price of these things how much work you have to do to get them to fit. I have heard that FAST has **** poor R+D and quality control, but now I have experienced it first hand. This is definitely my first and last FAST intake. For crying out loud, at least add a tab to hold the MAP sensor in.
I'm thinking of having my LS6 intake ported and pulling the FAST off and selling it.
All that being said - my car whistles as well once it warmed up. Its just a real short and low whistle when you first crack the throttle, during the transition from idle. It doesn't whistle at idle or when you are getting on it. I suspect the PCV or the purge hose as the FAST intake gas both pieces in non original angles.
The intake itself is nice enough, but it is obvious that FAST tries way to hard to make their intake fit all models of LS equipped cars, resulting in individual fitment issues for each model. I cant believe for the price of these things how much work you have to do to get them to fit. I have heard that FAST has **** poor R+D and quality control, but now I have experienced it first hand. This is definitely my first and last FAST intake. For crying out loud, at least add a tab to hold the MAP sensor in.
I'm thinking of having my LS6 intake ported and pulling the FAST off and selling it.
All that being said - my car whistles as well once it warmed up. Its just a real short and low whistle when you first crack the throttle, during the transition from idle. It doesn't whistle at idle or when you are getting on it. I suspect the PCV or the purge hose as the FAST intake gas both pieces in non original angles.
Interesting thread. I just installed a FAST intake on my 01 C5, I got a brand new 78mm model dirt cheap so I couldn't resist.
The intake itself is nice enough, but it is obvious that FAST tries way to hard to make their intake fit all models of LS equipped cars, resulting in individual fitment issues for each model. I cant believe for the price of these things how much work you have to do to get them to fit. I have heard that FAST has **** poor R+D and quality control, but now I have experienced it first hand. This is definitely my first and last FAST intake. For crying out loud, at least add a tab to hold the MAP sensor in.
I'm thinking of having my LS6 intake ported and pulling the FAST off and selling it.
All that being said - my car whistles as well once it warmed up. Its just a real short and low whistle when you first crack the throttle, during the transition from idle. It doesn't whistle at idle or when you are getting on it. I suspect the PCV or the purge hose as the FAST intake gas both pieces in non original angles.
The intake itself is nice enough, but it is obvious that FAST tries way to hard to make their intake fit all models of LS equipped cars, resulting in individual fitment issues for each model. I cant believe for the price of these things how much work you have to do to get them to fit. I have heard that FAST has **** poor R+D and quality control, but now I have experienced it first hand. This is definitely my first and last FAST intake. For crying out loud, at least add a tab to hold the MAP sensor in.
I'm thinking of having my LS6 intake ported and pulling the FAST off and selling it.
All that being said - my car whistles as well once it warmed up. Its just a real short and low whistle when you first crack the throttle, during the transition from idle. It doesn't whistle at idle or when you are getting on it. I suspect the PCV or the purge hose as the FAST intake gas both pieces in non original angles.
Tony @ AFR knows how to get rid of the whistle...
https://ls1tech.com/forums/generatio...whistle-2.html
https://ls1tech.com/forums/generatio...whistle-2.html
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo Thanks a million, I will give them a call. Do you remeber where you may have read it?
Ah the old simal-post lol.
...hey a couple-2-3 other things it could be if it's not a vacuum leak: it could be whistling through the IAC port in the throttle body, or through the port for the PCV's fresh air supply inlet. Or you might even have a stuck or backwards installed PCV valve.
I think the IAC motor moves a 'piston' in and out from blocking the port in the TB according to operating conditions (during cold start I'm guessing it's closed and then it opens once it warmed up, IDK could be the other way around).
PS you are using the special button head bolts for the valley pan, right? I hope the manifold isn't cracked!
...hey a couple-2-3 other things it could be if it's not a vacuum leak: it could be whistling through the IAC port in the throttle body, or through the port for the PCV's fresh air supply inlet. Or you might even have a stuck or backwards installed PCV valve.
I think the IAC motor moves a 'piston' in and out from blocking the port in the TB according to operating conditions (during cold start I'm guessing it's closed and then it opens once it warmed up, IDK could be the other way around).
PS you are using the special button head bolts for the valley pan, right? I hope the manifold isn't cracked!
