carb vaccum
Pro
Joined: May 2002
Posts: 726
Likes: 0
From: Petaluma CA
Re: carb vaccum (anniversary78)
Hi 78...putting your hand over the top of the carb would shut off air, making it run richer, as tho it had been too lean...but that doesn.t necessarily mean vac leak...could be carb out of adjustment. Anyway, you can check vacuum pressure, then check idle adjust screws, then vac hoses...good Saturday project...good luck
Thread Starter
Cruising
Joined: Aug 2002
Posts: 11
Likes: 0
From: new brighton mn
Re: carb vaccum (Stevo)
Stevo, thanks for the response! Just got the car from Reno Nev, I live in Minn could there be a issue here with the mixture due to the difference in the alltitude? Jeff
Tech Contributor
Joined: Aug 1999
Posts: 14,376
Likes: 6,375
From: At my Bar drinking and wrenching in Lafayette Colorado
Re: carb vaccum (anniversary78)
The '78s were set up pretty lean in their stock form through a combination of low float level and the rod/jet combination. Holding your hand over the carb and picking up some rpm is a verification of this lean condition. You can probably stand to pick up a little performance and a little better throttle response through a jet and/or rod change. You might also verify that your float level has not been lowered lower than the stock spec. You can pick up a copy of my Q-Jet tuning paper over in the CorvetteFaq section - this will give you some tuning tips for the condition you describe.
