70 L46 vacuum leak?

[Bill L.]

The headlights go up and down correctly. The passenger side is slow and it like the vacuum switch.

Could a bad switch result in a vacuum leak and cause a rough idle and acceleration?

The vacuum port on the carb is now blocked off and the car runs excellent. When I hook the vacuum line back up the problem returns.

I have followed the good Dr's vacuum line install diagram and it looks like it is correct.

Thanks, Bill

[Joseph K.]

Re: 70 L46 vacuum leak?

Bill,

Vacuum leaks are not that hard to find, you just have to be methodical about finding them. A vacuum pump would be helpful. The first thing you need to do is to isolate if it is on the wiper door or the head light side. After you do that look at your actuators and your valves they will loose a lot of vacuum if they are bad. There are several threads in the archives that will also help you. You are going through a very common problem with the early C3's.

Joe

[Alan S.]

Re: 70 L46 vacuum leak?

Hi Bill,
Joe's right about the good information in the archives. Look for 'winking' headlights and for Jack H.'s posts.
Since your 70 has a relay for each actuator I'd think the slowness you're seeing COULD be caused by a leak in the right-side relay or more likely a leak in the seals in the right-side actuator.
Good Luck!
Regards,
Alan

[Bill L.]

Re: 70 L46 vacuum leak?

I am pretty sure the passenger side vacuum switch is bad. I guess I am a little surprised about the apparent affect the leak has on engine performance.

I will continued to work through the process.

Alan - Now that the beast is running well are you planning to visit Jimmy Cone in Mt Airy any time soon. Maybe we can grab some ice cream and talk corvettes?


Bill

[Terry M.]

Re: 70 L46 vacuum leak?

C3 vacuum leaks are rarely from just one point -- especially when they get bad enough to affect performance. One point may be the worst offender, but I can almost guarantee you there will be multiple leaks when you start methodically diagnosing the system.

[Edward J.]

Re: 70 L46 vacuum leak?

Bill, you may have a headlamp vacuum canister seal leaking, those seals are reproduced. an easy check is plug the vaccum hoses at the headlamp canister with the engine running and see if the engine idle smooths out, if not head for the relay.they sometimes have a vacuum leak at the bottom of relay through the vent.

[Bill L.]

Re: 70 L46 vacuum leak?

I am 100% sure the one switch is leaking. I guess a vacuum pump is next so I can test all the components.

The good news is the vette is running great with the vacuum plugged

This much fun should be illegal.


Bill