Before we get started, I have been reading search results for about an hour.....and if you're about to pipe in and tell me to get an edelbrock, just PM me, and I'll send you my shipping address, so you can buy me one and send it to me. 600 holley, vacumn secondariy carb, I just rebuilt it, (spray carb cleaner, new gaskets, needles and seats and P valve) and it was fine around town. I took a little road trip, and now it's flooding in the secondaries. I readjusted the floats, checked the needle and seats in both bowls (blew through the feed tube while raising the float), they seemed to be working fine. I put the carb back on and it seemed fine for just a little bit, the started running really rich again. When I shut the engine down, I could hear fuel flowing, and sure enough, I had fuel puddling in the secondaries...... It's a 327, mechanical pump, fuel filter right before the carb inlet, brand new tank and 3/8 lines. I know that I need to verify the fuel pressure, but the mechanical pump shouldn't need a regulator, and it's been fine for a week or two around town, with an occasional high RPM romp..... What else could it be ??
Being a vacuum secondary something has got to be loose or warped back there. No metering block right? Just the plate screwed to the body?
Is it a 4150 or a 4160? ,4160's have no secondary metering block just a plate. If it is a 4150 it could be the PV, those things blowout very easily.
Had this problem my self .I ended converting floats to brass and changing the metering valve .By metering valve ,I mean the float adjustment needle .My secondary kept going out of whack and flooded car ....600 holley I read if you scratch the plastic float even with your fingernail it will sink .There is some protective coating on the float .Now I use brass....
Change rear float and you will be good. I have had good luck with the Nitrophyl floats but a new brass float is fine--you choose.
I'd pretty well agree that there is either a float or needle and seat problem. I think I'd pull the bowl off and pull them out and check them over closely. There may be a chunk of dirt or something that is hanging around in the seat and getting under the needle at times or the needle may be damaged. If it does have a power valve, a blown power valve can cause similar problems. I just pulled my 650 spreadbore off because of blown power valves (big assed backfire) and now am cussing the Qjet that I replaced it with (no guts and hard starting). What model and list # is the carb. We have some pretty sharp Holley and carb in general guys on here who may think out another solution. If you have the plastic floats you can usually tell if they are soaking up gas by holding them in your hand and feeling how much they weigh.
just verify the fuel pressure before you hunt too hard. Had a similar problem and finally identified it as too much pressure from a stock style pump. Bought a new regulator and the problem remained. Damn regulator was faulty. Without a fuel pressure gauge it would have been a nightmare to discover the problem. If you put the sidepipes back on, the problem will likely go away immediately. good luck, Chris!
I got it....thanks guys. It was some crap in the needle and seat, I just didn't find it until the 4th time it was apart.......I know, I'm an idiot......
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