FAST 102 Vacuum Leak problem
10-30-2010, 07:36 PM
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FAST 102 Vacuum Leak problem I installed a Fast 102 on my C5. Had to drop the motor to get it to fit. Had a vacuum leak and finally figured out it was setting on top of the water pump before being torqued down. I ground down the high spots and thought I had the problem taken care of. I started up the car no noise at all. I drove around for about 30 minutes and it started whistling again. I checked the clearance again with a mirror and decided to take some more off the top of the water pump. Tried it again with the same results. Seems like when the car gets good and warmed up it develops a vacuum leak. Yes I used blue locktite on my bolts and torqued them correctly. Any ideas out there ???
10-30-2010, 08:51 PM
#2
How about at the MAP sensor? And are you sure the intake is not resting on the valley pan? If you have milled heads it could get tight. I saw where one guy went so far as to counter bore the valley cover bolts for a flush fit bolt and extra clearance, his was touching even though he used the button head bolts that are supplied with the FAST intake. You can also try spraying carb cleaner in suspect areas while the motor runs, and if you get an increase in RPM, there's your Huckleberry. Just a couple thoughts.
...and holy smokes, what kind of car is it that you had to drop the motor to get the intake on?
...and holy smokes, what kind of car is it that you had to drop the motor to get the intake on?
10-30-2010, 09:07 PM
#3
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I installed a Fast 102 on my C5. Had to drop the motor to get it to fit. Had a vacuum leak and finally figured out it was setting on top of the water pump before being torqued down. I ground down the high spots and thought I had the problem taken care of. I started up the car no noise at all. I drove around for about 30 minutes and it started whistling again. I checked the clearance again with a mirror and decided to take some more off the top of the water pump. Tried it again with the same results. Seems like when the car gets good and warmed up it develops a vacuum leak. Yes I used blue locktite on my bolts and torqued them correctly. Any ideas out there ???
I installed a 95 PTM which the O ring was visibly not sealing underneath, also LS1 water pump was in the way due to me having heads that are milled.
SOLUTION: i went with a PTM 102 T/B and an LS2 water pump that doesn't have the protrusion on the top & next to the horizontal water intake pipe.
I believe from my searching etc you will find that the 95mm fast T/b is also ok to use.
G/Luck
10-31-2010, 12:02 AM
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The car is a 1997 Corvette 51,000 miles. It was bone stock when I got it out of Houston a couple months ago. It is in excellent condition. I've added a Callaway Honker CAI, American Racing Headers without cats, Magna flows, and now the FAST 102 intake with an LS2 TB. This intake is the biggest pain I have ever experienced. 1st it wouldn't fit under the wiper cowl at the back of the motor so I had to lower the motor 1/4". That part was easy. Grinding on the water pump pisses me off. I do see just a tad bit of the TB seal at the bottom. I wouldn't think that would be the issue. If it was the TB I would think it would do it right off the bat when I start it.
10-31-2010, 09:26 AM
#6
The car is a 1997 Corvette 51,000 miles. It was bone stock when I got it out of Houston a couple months ago. It is in excellent condition. I've added a Callaway Honker CAI, American Racing Headers without cats, Magna flows, and now the FAST 102 intake with an LS2 TB. This intake is the biggest pain I have ever experienced. 1st it wouldn't fit under the wiper cowl at the back of the motor so I had to lower the motor 1/4". That part was easy. Grinding on the water pump pisses me off. I do see just a tad bit of the TB seal at the bottom. I wouldn't think that would be the issue. If it was the TB I would think it would do it right off the bat when I start it.
I'd go over all the bolts and makes sure nothing was worked it's way loose. Try the carb spray test - carefully. And like 'ls1 1990 VN' be mindful of of TB fitment and seal, all the seal for that matter. Good luck,bro.
10-31-2010, 11:15 PM
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Now I am really pissed. I decided that the seal showing was not good so I built a spacer plate to seal the the throttle body completely. I was sure that was it. I took it out again and the same thing happened. I tried the carb cleaner idea everywhere around the outside I could hit with no change in the idle. I haven't seen any indication that the intake is hitting on the bottom. All the bolts are tight with blue locktite everytime and stay tight after I have double checked them. I completely replaced all the seals inside the intake. I guess I could countersink the valley plate and put flat head screws on just to make sure. I am about to take this thing out back and blow it up. I would if I hadn't dropped a grand on it and getting it ported to boot.
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11-01-2010, 12:14 AM
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Now I am really pissed. I decided that the seal showing was not good so I built a spacer plate to seal the the throttle body completely. I was sure that was it. I took it out again and the same thing happened. I tried the carb cleaner idea everywhere around the outside I could hit with no change in the idle. I haven't seen any indication that the intake is hitting on the bottom. All the bolts are tight with blue locktite everytime and stay tight after I have double checked them. I completely replaced all the seals inside the intake. I guess I could countersink the valley plate and put flat head screws on just to make sure. I am about to take this thing out back and blow it up. I would if I hadn't dropped a grand on it and getting it ported to boot.
Otherwise make double sure that under the bottom of T/B is still not fouling on the water pump at the back.
Not sure on LS2 T/B fitment though, you may have to use the T/Bs suggested for correct fitment & or the LS2 waterpump.
11-01-2010, 12:37 AM
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The groove is in the intake and the seal sets in it. The throttle body just fits against it. The plate I made is aluminum and I used gasket sealer on it between the Throttle body and the plate. I am sure there is no leak and the seal is good. I sprayed around the throttle body with carb cleaner while the motor was running and there was no change in the idle. I just can't figure this out. I checked it all over when I replaced the seals inside the intake there were not cracks.
11-01-2010, 03:34 AM
#11
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Not sure how yours is setup, but how about PCV valve, i had one years ago on an iron 350ci that whistled after pressure built up, it drove me crazy for a couple of months till someone picked what was wrong.
11-01-2010, 06:15 AM
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I will pull it and check it out or replace it. I never even thought of that. Auckland New Zealand! Thats amazing. I'm an old guy. I would have never dreamed I would be getting tips from someone half way around the world from me. I always have a chat with you folks at the World of Outlaw Sprint Car Nationals in Knoxville Iowa every year. Thanks for sharing your knowledge.
11-01-2010, 11:44 AM
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I am in a similar situation. Just installed a new ported FAST 102, and it was a major PITA. I think mine may be whistling slightly. The manifold sits on the waterpump. I didnt even know that would be an issue. I couldnt mount the TB adapter, and so I had to cut a groove out of it and also about 1/4" from the bottom (using of all things, a freaking hacksaw) I haven't been this pissed in a while.
11-01-2010, 12:09 PM
#14
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I will pull it and check it out or replace it. I never even thought of that. Auckland New Zealand! Thats amazing. I'm an old guy. I would have never dreamed I would be getting tips from someone half way around the world from me. I always have a chat with you folks at the World of Outlaw Sprint Car Nationals in Knoxville Iowa every year. Thanks for sharing your knowledge.
Sir Harmony, you also may have been better to have used the LS2 water pump also as it clears the Manifold.
11-01-2010, 08:22 PM
#15
I'm about to mount a FAST 102 with a NW 102mm TB on an LS2 with L92 heads and a Meziere EWP. I hope it clears! As it is already, one of the power steering pump hex cap bolts won't clear the EWP, I have to use an allen bolt.
BTW, I'm probably older than both of you @ 48.
BTW, I'm probably older than both of you @ 48.
11-01-2010, 08:59 PM
#16
I'm about to mount a FAST 102 with a NW 102mm TB on an LS2 with L92 heads and a Meziere EWP. I hope it clears! As it is already, one of the power steering pump hex cap bolts won't clear the EWP, I have to use an allen bolt.
BTW, I'm probably older than both of you @ 48.
BTW, I'm probably older than both of you @ 48.
11-01-2010, 09:53 PM
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Bucketlist1957 ought to give you a clue as to how old I am. I got ya beat. I replaced the PCV and capped off the EVAP purge solenoid and switch at the manifold unplugged the electrical connectors and capped the line to the EVAP canister. The only thing that did was make my car throw a code. I am to tired to look it up tonight. I will try again tomorrow.
11-01-2010, 10:55 PM
#18
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I'm about to mount a FAST 102 with a NW 102mm TB on an LS2 with L92 heads and a Meziere EWP. I hope it clears! As it is already, one of the power steering pump hex cap bolts won't clear the EWP, I have to use an allen bolt.
BTW, I'm probably older than both of you @ 48.
BTW, I'm probably older than both of you @ 48.
11-01-2010, 11:13 PM
#19
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Bucketlist1957 ought to give you a clue as to how old I am. I got ya beat. I replaced the PCV and capped off the EVAP purge solenoid and switch at the manifold unplugged the electrical connectors and capped the line to the EVAP canister. The only thing that did was make my car throw a code. I am to tired to look it up tonight. I will try again tomorrow.
Mines still not going as I've been waiting for my LS2 thermostat & housing that didn't come with the water pump since supposedly 22nd Oct, USPS.
Would've thought TSP could have been a bit more on to it, knowing the circumstances fully, with me getting the LS2 pump through them to make sure it was complete.
11-02-2010, 10:05 AM
#20
Bucketlist1957 ought to give you a clue as to how old I am. I got ya beat. I replaced the PCV and capped off the EVAP purge solenoid and switch at the manifold unplugged the electrical connectors and capped the line to the EVAP canister. The only thing that did was make my car throw a code. I am to tired to look it up tonight. I will try again tomorrow.
Will do.