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I just bought this 1979 Corvette a few weeks back and learning about Corvettes. It's been 17 years since I owned a hot rod. My last one was a 1932 Ford 5 window coupe Hiboy with a Chevy 350.
The demon.
So I took the Vette out for a spin two weeks ago before it snowed and then put it in the garage. Last week I started it but it would not idle. Start right up every time but would not idle at all. So today I went to change the gas filter, thinking it could be dirty and check vacuum lines. When I removed the air filter assembly I noticed the PCV valve line was not connected to the carb vacuum port and reconnecting should solve my problem. Sure enough it did the trick and now she runs just fine in the garage. Proud of myself for figuring this malfunction out.
Now can anyone tell me where this line should go that is capped off?
Looks like that is the line that re-directs the air
cleaner to pull 'warm' air from around the exhaust manifolds during cold startup. Mainly an emissions thing - it won't hurt a thing leaving it as-is. If you want to reconnect it, it goes to one of the ported vacuum switches in (or near) the thermostat housing.
In 1979 (at least non-California) the vacuum connection is in the center of the carburetor base at the rear. The three "T" connections are: 1) vacuum source; 2) vacuum motor on side snorkel; 3) thermostatic vacuum valve in the base of the air cleaner.
The other thermostatic vacuum valve connection goes to the vacuum motor on the front snorkel.
With a cold engine both snorkels close and air is drawn through the corrugated pipe connected to the "heat stove" over the passenger side exhaust manifold. As the engine warms, the front snorkel opens.
The side snorkel is only open during wide-open throttle when vacuum drops to near zero.
The dual snorkel system is a very good cold air intake suitable for significantly more engine displacement/RPM than the stock motor.
Yes the ThermAC (this system) is an emission control. Its purpose is to help the engine get to operating temperature more quickly--something it certainly does--and has zero impact on performance.
1979 Corvette would not idle
