Hey guys, I rebuilt a 600 Edelbrock carb today. Now it floods from the primaries at idle. It's dribbling out so much fuel that the idle screws do nothing. I took the top back off of the carb and adjusted the floats to 5/16. It still does the same thing. I was using a Carter kit. Edelbrock says to use 7/16, but I'm not sure that's the problem. Anything else I might have done wrong?
I put on a brand new stock mechanical fuel pump today. It's a pretty much stock 302. Not sure about fuel pressure though. The old fuel pump was starting to crap out, so I thought it might have been starving, until I fired it back up and did more investigation.
I needed to use a regulator on three vehicles with stock pumps. My international truck was putting out 8.5 psi . Much better at 4 psi for the carb. I would do that before messing with the carb at all.
The Edlebrok spec for the float is 7/16th (least on the 1407 I just went through), 5/16th would be higher, right? Yeah, and FP is always a concern with them.
I was hoping I had it right...was just a few weeks ago when I went through mine...but if 7/16th will lower it...you're looking at an 1/8th of an inch...huge.
The inlet chamber leading up to the needle valve must be perfectly clean on these carbs. The slightest piece of debris will allow that needle to seep fuel.
Like said earlier, check fuel pressure and you will probably need a regulator to get it to 4 psi. I think the Edelbrock calls for around 5 . Mine is set to 4 to 4.5 and works great.
The Carter AFB Kit I had said to put the floats at 5/16. Sounds like I definitely need to put it at 7/16. Also, my dad put a regulator on it today. He even rabbit down to 2 psi, but it still didn't help.
I've owned and worked on many of these, sounds like improper float setting. This recently happened to a buddy of mine, I told him it sounded like a float issue, he sent me a pic of the floats. They were way out of adjustment. Download the Edelbrock carb manual.
How much vacuum does your engine have at idle? If you don't know, you can get a vacuum gauge from your nearest parts store to check. I ask this question because if the springs that dictate step up rod movement are too strong then you will get flooding at the primaries. Step up springs should be roughly half the engine vacuum at idle. I also concur that the floats need to be set at 7/16.
Not sure, but the step up springs are pretty light. I'm guessing stock for the car, but you can watch them pull all the way in when the car is started. I definitely need to re-adjust the floats to 7/16.
Well, I readjusted the floats, they are correct now. The needles are new and clean. The car is now running and not flooding. But, the right idle screw does nothing and it only runs on 4 cylinders when in gear. It's an automatic, so it's pulling down the rpm really low when in gear. At neutral idle, it seems to run fine.
I had this problem on my Edelbrock, fuel dripping in at idle, Stripped and clean a half dozen times, with no change, adjusted floats several times etc. Google research told me there is a tiny bleed hole in the bit that goes in the primary. It is tiny, but found it blocked with hard crud from dried out fuel. I think it was the very top idle air bleed that cured my problem.
Thanks for the image man, that helps a lot. I cleaned all of the small holes when I rebuilt it. They were pretty nasty. I believe I should probably shoot some carb cleaner in it and blast it with compressed air, like the image shows.
I had the same problem until I reduced the fuel pressure. Sent from my iPhone using The H.A.M.B. mobile app
Yes. I bought a refurbished Edelbrock that flooded on it's first installation. At first I cleaned the needle and seats but then it flooded again. Turns out the inlet chambers leading into the needle valves were quite dirty. Some refurb, huh? Just as a sidenote, today's gas can wreak havoc on old rubber fuel lines. They tend to disintegrate from the inside, shedding rubber particles into the needle seats.
Buy a fuel pressure regulator, hook it up and lock it down at no more than 4.5 psi. Sent from my SM-G920T using The H.A.M.B. mobile app
Hey guys, I got it fixed. Just the float problem. I put a regulator on it and it didn't help. Took it back apart and then adjusted the floats. We also shot some carb cleaner in the idle screw hole and put some compressed air to it. Now it runs perfectly!