97QuasarBlue3.8

This isn't actually Camaro related--it's for a '72 K5 Blazer with the 4MV Quadrajet.

The truck was starting hard, and would sometimes die after being started hot with just a little throttle. However, the situation was pretty predictable.

I got the great idea this weekend to rebuild the carb. Pulled everything apart, cleaned it up, replaced as many applicable parts that came in the rebuild kit. The existing float was in decent shape, so I checked the level and called it good. I put it all back together, and attempted my first start.

It took a bit--filling the bowl, I guess, and then caught. First thing was the awful smoke (like if you leave the choke out too long). Revved it up a little, there was some moisture, more smoke. It was running "rough." When you give it some gas, along with the awful nasty smoke is black soot -- fuel?

Couple of problems:

1. There is some fuel coming out of the accelerator pump when its running.
2. It will not run at idle for very long. I think it fouls up and then dies.
3. The idle mixture screws don't seem to do much.
4. When I shut the car off, a bunch of vapor comes out of the carb (if the air cleaner is off)

Help! Looking for a place to start...

Angelis83LT

it is flooding severely. Which tells me that if the mixture screws are not doing much, fuel is pouring into the carb somewhere else. It has been a while since I bothered to look at one of the quadrajets in the garage. I would tend to thing that.. not sure where to start with it. It could be float, it could be the metering rods, or the accelerator pump. One of those things is letting waaaaay to much fuel into it.

cnorton

The odds are very high that you have some sort of issue with the needle/seat or the float/float level. That's the place to start looking.

ardmsrt

New float is only a few bucks, always replacew with a rebuild well worth it. Sounds like floats not sutting off needle valve or maybe needle valve malfunction, or even check ball.

3TAS4ME

First off, did you compare the new gaskets with the old? Sometimes the kits come with different gaskets depending on the application. Each kit covers multiple carb applications. Second, did you install a new needle/seat? Did you place the small metal ring gasket under the seat before installing it? Did you hang the needle valve on the float properly? If the needle valve is not installed on the float properly, it will not shut the fuel supply off to the bowl. Float level is also critical, if you did not set it correctly, take the air horn off and do it again. Remove the air horn and take a picture without disturbing anything and I can probably tell you what is wrong.