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while trying to put this car back to stock, I discovered my throttle body only has one vacuum port on the right side. Supposed to have two from my understanding and as far as I know this is all original equipment.
Check out the photo and if anyone knows about or has run one like this please let me know how you hooked up your vacuum hoses..
If you are talking about the one at the bottom with the surface rust on it, that is actually a coolant port. There is another at the bottom front of the TB.
He's referring to the large vacuum port. I don't recall ever seeing a TB with only one but I don't deal with MAF cars very often. Off memory the top one was for the crank case vent from the valve cover and the bottom one that's plugged is supposed to be the charcoal canister vent. The purge solenoid will just vent to the atmosphere if you don't hook it up.
Is it plugged? Or did the tube just work it's way out?
If it was ever open and went through then it's been plugged. I will have to take a real close look at it when I get home from work and see if it ever went all the way through and it's just plugged.
I asked Bob this but do you think it would work if I connected the canister to the one port that's there and just put a breather on the valve cover??
Look at the arrows concerning those lines...if the vapor canister purges to the same line that provides "air in" for the PCV then gas fumes will go to your crankcase. That's where you don't want gasoline fumes. I'm willing to bet that the upper TB port doesn't have any vacuum to it to provide the PCV with clean air to circulate the crankcase atmosphere. The lower TB port likely has vacuum to send gas fumes from the canister to the combustion chambers.
OK guys, just got home a looked real close. It is not plugged. It is cast that way and there is no opening on the inside into the channel..???
Googled the part number on the bottom and got an Ebay hit advertising it as a C4 Corvette TB and it is the same as the one I've got...?? Think this thing will work?
Look at the arrows concerning those lines...if the vapor canister purges to the same line that provides "air in" for the PCV then gas fumes will go to your crankcase. That's where you don't want gasoline fumes. I'm willing to bet that the upper TB port doesn't have any vacuum to it to provide the PCV with clean air to circulate the crankcase atmosphere. The lower TB port likely has vacuum to send gas fumes from the canister to the combustion chambers.
Sorry, you lost me there a little. Since I only have a top port and that is the one that provides fresh air into the crankcase, what do I do with the line from the canister?
You could drill it through, tap and install a fitting for the charcoal canister hose.
Or you could trade it to a C4 guy and get the correct one you need.
The IROC being yellow is just coincidence actually. I used to drive by it in this guy's driveway all the time and finally one day I knocked on his door and told him to call me if he was ever interested in selling it. He called me back about three weeks later and told me his wife thinks he has too many projects and I bought it.
My son thinks it's really cool we both have yellow sports cars and when it comes time for paint, we are going to paint it the original color.. Problem is, we get this thing all restored and I may keep it and just get him a Honda or something!! I love these IROC's and always have. But that Z06..Wow is the only thing I can say about it, what a machine...
06-11-2015, 11:24 AM
