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Discussion Starter #1
Hello,
I am pretty new at working on engines, so if I am asking a dumb question, I apologize. I have a 79 Camaro that came with a 350. It was a dud, so I replaced the entire top of the engine. New cam, Edelbrock RPM intake, Chevy vortech heads, new valve springs and 1:6 roller rockers, new HEI distributor, Hooker headers, and a Holley 750 double-pumper. My problem is this: When I start the car, it starts right up. Got the timing set and such. But the engine won't stay running normal to idle. It kind of sounds like the engine is drowning?? It doesn't quit, but it sure is trying. So after I turn off the engine, I quickly checked the engine compartment. The secondarys(I think, closest to driver and without choke) on the carb are continuing to squirt fuel into the manifold. The fuel then is leaking out between carb and manifold. This flooding can't be normal. By the way, all these parts, including the carb, are brand new. Any help would be greatly appreciated. Thanks!!
 

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The first step is to check the float levels. I would probably lower the rear one if it's flooding before I attempted to check it. To lower it, loosen the screw on top of the float bowl while holding the nut with a 5/8" wrench. After loosening turn the nut clockwise 1/2 to 3/4 turn and re-tighten the screw while holding the nut. See if it is still flooding. If it's not you are ready to set the float level. Remove the round screw on the side of the bowl. I like to put a towel under it to prevent gas from spilling. Get the flooding problem fixed first before setting the float level as if it's flooding it's going to pump a lot of gas out the side screw hole when you remove it. With the engine running, the correct level will have the gas just trickling out the hole with a gentle shaking back and forth of the car. Clockwise with the 5/8" nut lowers the level and counter-clockwise raises it. Lock down the screw when you have it where you want it. Front and rear can be adjusted the same.

If it's still flooding you need to pull the needle and seat out of the carb. It simply un-screws counter clockwise. Check to make sure there isn't any debris (rubber fuel line, etc. ) stuck in the needle/seat. Blow it out with compressed air if available. Then re-install and set the float. I like to set it low (screwed down more) and raise it to get the proper level when I have the engine idling.

If the above items don't fix it you need to look at fuel pressure. Holley carbs don't like more than 8psi but can flood at less pressure. Other items to check would be a sunk float (float fills with gas through a small pinhole and sits on the bottom of the bowl instead of floating causing the needle and seat to remain open; blocked vent tube; sometimes in shipping if the carb is dropped the vent tube will slice through the cardboard packaging and put a perfect little circle of paper inside the vent tube, causing it to flood. There are more things but I'd bet one of the above will fix it. Start with the simple stuff and go from there.
 

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Discussion Starter #3
Hello Camcojb,

I tried lowering the float level, but the carb still floods. So I would like to check the needle and seat. Umm, could you tell me what and where these are? This is my first time working with any carburetor. Thanks for any help.

BTW: I have a Carter manual fuel pump going to a Summit dual feed line w/pressure guage. The fuel pressure seems okay(6psi).
 

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The round screw/hex nut assembly you adjusted is attached directly to the needle and seat. Just unscrew the 5/8" nut until it comes out the top. Installation is the reverse; just watch the o-ring and make sure not to pinch it. Generally it goes right back in.

One other thing. I had a brand new Holley that after a few miles of driving started to flood on the secondary side. I did all the above and nothing worked. Finally I replaced the needle/seat assembly; problem solved. There was no evidence of any problems with the other needle/seat; it just wouldn't seal so it flooded. Since it just happened to me last month I thought I would mention it.

[This message has been edited by Camcojb (edited 06-06-2000).]
 

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Discussion Starter #5
I pulled the needle assembly out of the carb and checked it out. I think I found the trouble. There were a few tiny bits of something on the valve seat. Must have been keeping the valve open, and then it floods. Cleaned the valve and seat, and seems to have solved it. Thank you very much Camcojb!
 

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That's great! However that debris is probably in the bowls and could cause the problem again. You really should pull the bowls off(front and rear)and clean them out. I wouldn't be surprised if the debris came from the chrome fuel line!

P.S. Have some new metering block and bowl gaskets before you start; they will almost definitely tear and have to be scraped off when you take the bowls off. It also would be a good idea to flush out the fuel lines before you re-connect them. The debris came from somewhere. Just dis-connect the coil and turn the engine over with the fuel line in a coffee can. Be cautious of open flame, ventilation, etc.

[This message has been edited by Camcojb (edited 06-07-2000).]

[This message has been edited by Camcojb (edited 06-07-2000).]
 
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