vaccum leak

[slammed70gmc]

Ok I'm trying to find a vaccum leak, already sparyed the intake and carb gaskest, and replaced them when i lost all my coolant. There is only the vaccum advance, pcv, and the vaccum modulator hooked up and their not leaking. its a loud hiss and it gets louder with no air cleaner. I'm out of ideas.

THANKS!

[LockDoc]

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What do you have for a carb and intake? I had a similar problem and it was because I had a square bore manifold and a spread bore carb. Once I put an adapter on it the vacuum leak went bye-bye.... Just a thought.

If your leak is that loud it may be a port on the carb that isn't capped.

LockDoc

[68gmsee]

Looks like you've checked the obvious. I don't know if you have a mechanic's stethoscope but I've always found out that I need help to isolate the hard to find noises.

My favorite noise finder is a 3 foot long piece of garden hose. I can snake it into hard to get to places and works great for me. The stethoscope is good to free up one of the hands in case you need to flex tubes or rev the carb up, etc...

[Longhorn Man]

make sure it isn't from the carb its self... down in the body. Some carbs make a lot of noise.
your comment of;

its a loud hiss and it gets louder with no air cleaner

makes me think that.

[slammed70gmc]

well its got a edelbrock carb and manifold. No ports are open. And I'm having a hard time trying to set the mixture right its always to rich, and its had two different edelrock carbs on it.
THANKS!

[ChevLoRay]

My truck had an Edelbrock 1401 on a stock intake, with an adapter, when I bought it. It, too, ran rich....burn your eyes!! When I replaced the intake with an Edelbrock and an Edelbrock 1901 (Q-Jet), the rich combustion odors went away. In fact, the combustion temps went up and I had to put a heat shield on the starter, due to heat soak.

If your carb is also a 1401, they are jetted rich, from the factory. Go to www.edelbrock.com and you can access their tech pages, which will tell you waaaaaaay more than you probably want to know about all aspects of setting these carbs.

[VetteVet]

Here'sa great site for eelbrock tuning.
http://www.edelbrock.com/automotive_...ers_manual.pdf

[LockDoc]

Originally Posted by slammed70gmc

well its got a edelbrock carb and manifold. No ports are open. And I'm having a hard time trying to set the mixture right its always to rich, and its had two different edelrock carbs on it.
THANKS!

That's exactly what my '39 Ford coupe was doing. Even though the carb and intake are both Edelbrock one could be square bore and one could be spread bore. If that is the case it wont seal without the adapter plate. Just something to check....

LockDoc

[slammed70gmc]

well they are both for sure square bores. it does have a carb spacer though.