So I'm driving down 3rd street, going to school, 4th Gen Z28 that I see every time I go to school revs at me, so I prepare to get annhilated at the next stop light. I put my foot on the brakes to slow down and my car dies. It takes me a good while to get it to start again and when it does start, i have to keep it at 1500RPMs just to get it to run, and even then it misses like crazy. I limp it back home (never made it to school), shut it off, pop the hood and see a nice stream of gas dribbling from the secondaries into the engine and I have gas all over my intake manifold (it looks like gas leaked fom the ends of the shafts the butterflies are attached to). The only thing I've done to my carb. lately is lower the float level on the secondaries because my car used to let out a small amount of black smoke when I floored it. It ran just fine last night after I did that. My friend suggests that I make sure I lowered the float level instead of raising it. I go out to my car after I let it cool for a while and take the screw out of the needle and seat so I can pull them out to make sure nothing is stuck in them...about an inch long jet of gas shoots out of the hole and goes all over my engine, great. I know there may be a small amount of gas that may come out of there, but not a huge stream. I have no clue what is wrong with it, can somebody out there please help me?

Thanks

 

This is a Holley, I assume?

 

Oh, yes it is a Holley, forgot to add that. 600cfm, vacuum secondaries.

 

You could have a stuck float, or crud in the needle and seat.

Adjusting the float level isn't the right way to get rid of your black smoke.

 

I'll chech them when it cools all the way...do you know how to fix the smoke??? Thanks for the replies.

 

It's flooding.
Either clean out the needle & seats or replace them as neccessary.
Make sure the float level is adjusted properly, and check your power valve.

First get someone who knows there way around a carburetor.

 

Fixed the secondary problem, it was a small piece of rubber stuck in there. Now, how do I fix the black smoke problem? It only does it when its mostly or all the way to the floor.

 

Replace the spark plugs. They are carbon fouled from the dripping secondarys. Carbon fouled spark plugs cause misfireing, especually at or near WOT.
The black smoke is unburned fuel. The cure is to replace the sparkplugs with new ones. Be sure to gap them to .035"
Replace the fuel filter too.

 

The plugs are practically brand new and its done this since I rebuild the carb. I'm gonna get a new fuel filter soon.

 

New yes but now finished. Plugs are cheap. Get a fuel filter sooner or you'll have dribbling fuel in the carb again.

 

Ok, it looks like I'm getting new plugs too.
This is going to be the 3rd set of plugs this car's been thru since I rebuilt the engine 2600 miles ago. It seems to like to eat them, every 900 miles or so, I've had to get new ones due to hard starting and misfiring. Cleaning them doesn't seem to work. Is there anyhing I can do to keep them longer?

 

Fix your rich condition, probably.

 

Burp the wallet and splurge for a new $5 fuel filter so that your carb doesn't flood out any more.
Inspect the whole secondary side of the ignition system, new or not.... coil, cap, rotor, wires and plugs all have to be up to snuff.

 

So how did that check of the powervalve go?

Once you get the fueling problem fixed your plugs will be fine for a very long time.

 

Powervalve checked out OK.