Hope everyone doesn't hate me after all these questions, but i'm just learning here.....

Regarding my vacuum system- I have an '81 and I took off all the emission crap- air pump and everything else- my question is... There are about 4 vacuum lines running from the vacuum pump that are just dangling and not going anywhere- it doesn't hurt the performance(I don't think- doesn't feel like it anyways), but I was wondering if that would be a cause of why my headlights aren't working as properly as they should???

Thanks again for the answers in advance.

 

Check out this page for vaccuum troubleshooting.
http://www.corvette-101.com/vacuum.htm

 

i've got a 70, so excuse my lack of knowledge, but what vacuum pump are you referring to? the vacuum should come off the manifold. are you referring to the smog air pump?

 

Yea, there is no Vac pump. There IS an AIR pump tho. You can delete the air pump and pretty much everything connected to it as long as you plug the vac source lines going to the pump and valves.

 

it's the black round cylinder below the master cylinder and below the transducer... what exactly is that thing? the smog pump?

So the vacuum for the headlight comes from the manifold?

 

That sounds like the Evaporative canister for the fuel tank return line. If it is I would keep it connected, it doesn't rob any power from the engine and helps keep the fuel smell down when you turn the car off, especially if you keep your car in the garage.

 

That is correct, the vacuum for your headlight come from a tee fitting behind the carburetor on your intake manifold. This tee fitting probably has 3 tees on it, one for the headlights, one for the cruise control, and one for the transmission. At least that how it is on my car and I imagine that they should be very similar.

 

So with those 4 hoses that aren't connected to anything now- should I just leave them be- or do they need to go somewhere?

 

surgn,
You really need to obtain a Workshop Manual and an Assembly Instruction Manual for your particular year and once you read them, you will find the schematics for all of your hoses.

The canister under your m.c. will be the evaporative canister and is needed for two reasons. One is to vent the fuel tank while the car is being driven and the fuel is being pumped out, creating a lower pressure in the fuel tank (or trying to!) so you should have an unbroken line going from the canister to the fuel tank. The second is to absorb petrol vapours from the carb while stationary and to allow them to be drawn into the engine and burnt while it is running.

Any broken or disconnected lines here will result in petrol smells and the potential of fire, a definite .

As said before, you can remove the A.I.R. pump without hurting performance, but don't throw it away, they're worth money. All of the other vacuum lines need to go somewhere and not be open to atmosphere, otherwise you will have trouble keeping vacuum in the system. This will affect your ignition timing, EFE valve, EGR valve and headlight operation.

Ask another Corvette owner in your are to help you if you wish, but it's all pretty straightforward once you have the manuals.

Regards from Down Under

aussiejohn

 

Plug up the unconnected vacuum hoses otherwise (depending on your engine temperature) you will have Vacuum leaks and low vacuum to operate your headlights

 

thanks everyone! And to happiedayz remark about pluggin up the hoses- should I just take them off and cap the outlets from the evaporative canister?

 

Hey guys- sorry to have to bring this back up, but I wanted to know if I could cap these lines and remove the hoses? Thanks again. Last question for at least a week

 

Are you listening? supervette77 is right! If you leave it unhooked, you will actually waste fuel and have problems with hot starts from heat soak. GET AN '81 GM SHOP MANUAL! You can find them on ebay; best investment you can make right now! God bless, Sensei

 

Ouch- gotcha... will do