Air_Adam

Hey guys, got a little problem.

I think I have a vaccum leak somewere on my engine, but I can't find one anywere. All of the unused vacuum ports on the carb have been properly plugged, and as far as I can tell, none of the existing ones are leaking. That includes the PCV, the one on the back of the carb that goes somewere under the firewall, the brake booster...

Is there anywere else it could be? I was thinking, since I removed the EGR, maybe there is a leak at the other end of the hose that went to the valve on the intake manifold? I have no idea were it went in the first place, because during the engine swap, my uncle did most of that stuff (i didn't know much back then) so were did it go to?

These are all '83 L69 parts on top of a '79 350. That includes carb, dissy, intake and exhaust. Computer is still in use and it doesn't throw any codes.

Here is a pic of what I still have hooked up to the carb. Everything else has been plugged:

cr125r

try pinching off the lines temporarily, or u can try the propane trick

Air_Adam

Propane trick? Go on....

yanfoo

get a can of Carb cleaner or brake cleaner or intake cleaner...
then spray the vacuum lines you still have, if any change of the engine, like a stumble is found... you found it.
Also spray the botom of the carb to check the baseplate gasket.

Can you tell us why you think you got a vacuum leak? what is the engine?

cr125r

oops, i guess i shouldve explained. same as above just with propane(unlit)

Air_Adam

Well, I didn't think I had one untill my uncle brought it up. He gave my car a minor tune-up about a week ago (timing, carb tune, etc) and he was saying I may have a vacuum leak. He says this because he says that when the engine is idling, and you hold your hand tightly over the primaries, you should be able to choke the engine of air enough to just about stall it, yet it didn't change how it ran at all. He knows his stuff too.. he's been a professional mechanic for the last 20 years, and was a HUGE help in installing the 350 in my car, so I know he knows what he is talking about.

A vacuum leak would also explain my horrid gas mileage of about 6 mpg around town on a very tame 350.