TBI coolant by-pass
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Joined: Oct 2007
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From: baltimore ohio
TBI coolant by-pass
I have an 86 w/82k on it. I am thinking of doing the coolant by-pass on the TBI. What do I need? What am I looking at? Also, the car has the stock exhaust, what type of system should I look at(cat back, eliminate cats and resonater)? Thanks for any imput
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
On the 86 TPI, coolant flows through the base of the of the throttle body; using two hoses. One is for coolant "In" and the other is for coolant "Out" One hose is short and the other much longer.
One hose (the longer of the two) is connected to the passenger side of the Throttle Body and the other one on the front of the TB.
Simple remove the two hoses where they connect to the Throttle Body and then connect them together. Bingo! The Throttle Body is by-passed and no coolant flows through the TB.
Jake
One hose (the longer of the two) is connected to the passenger side of the Throttle Body and the other one on the front of the TB.
Simple remove the two hoses where they connect to the Throttle Body and then connect them together. Bingo! The Throttle Body is by-passed and no coolant flows through the TB.
Jake
Racer
Joined: Feb 2004
Posts: 265
Likes: 1
From: Irwindale Ca
Ahh yes, like the other posters said, there are two hoses. They seem to hook them together. Although my first short hose from the engine to the TB was U shaped so hard to hook to the secondary hose from the TB to the heater. I just took the u hose off and scrapped it. I bought a brand new hose, a bit longer , plugged it into the inlet of the heater core where the other longer hose was and looped it around the ac pulley toward the second nipple at the engine. Basically bypassing the TB. That TB coolant is just to warm up the TB faster. Not much difference. Just easier to maintain and alot cheaper than buying that small preformed plastic hose that cost a million bucks haha.
Team Owner
Joined: Dec 2000
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From: Phila., PA burbs
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Team Owner
Joined: Jan 2003
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From: Summerland B.C. Canada
I routed my new hose under the AC compressor(through it's bracket).
You can see it here, it's the middle hose of the 3(left side of AC compressor). After that bend, it's out of sight and out of mind.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
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From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
I have an 86, and I bypassed the heat to the throttle body.
NAPA sells a 5/8 heater hose that is 4 feet long and has a molded 90* end and the part number is 9814.
I put the 90* hose on the manifold, and sent the other end of the hose to the heater shut off.
Later, when I installed the water/oil cooler under the oil filter, I cut some more of the hose, and put it to the "T" next to the A/C compressor, and routed the "T" to the heater valve, and the other end to the pipe that snakes around to the oil filter area.
The down side of this is the price of the hose is $20.00
NAPA sells a 5/8 heater hose that is 4 feet long and has a molded 90* end and the part number is 9814.
I put the 90* hose on the manifold, and sent the other end of the hose to the heater shut off.
Later, when I installed the water/oil cooler under the oil filter, I cut some more of the hose, and put it to the "T" next to the A/C compressor, and routed the "T" to the heater valve, and the other end to the pipe that snakes around to the oil filter area.
The down side of this is the price of the hose is $20.00
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
Throttle Body Bypass
Also, if you do the bypass, just keep all old parts so you can go back if needed or wanted.
There are kits that are inexpensive available at Ecklers, Mid-America, and Corvette Central with instructions included.
Last edited by l98tpi; Dec 2, 2008 at 10:05 PM. Reason: spelling
Team Owner
Joined: Dec 2000
Posts: 21,094
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From: Phila., PA burbs
One question you may want to answer before you do the bypass is whether or not you're going to drive this car during the winter. If you are you may want to wait until temps are consistently above 45 degress F outside. The reason your coolant flows through the throttle body is to keep it from icing up during cold weather. It will not be a good thing for you if your tb ices up and your blades get stuck open.
Pro
Joined: Oct 2008
Posts: 706
Likes: 265
From: Jyväskylä, FINLAND
Also, no problems. Wrote about it in this thread: http://forums.corvetteforum.com/c4-t...post1567680291
