I have a edlebrock 600 1406 hooked on a rpm preformer manifold. The problem I'm having is when I block all the vac ports except the one I'm using which is my distributor, my motor dies. As long as I have the power brake booster vac open it's stays running. My car has no power brakes so I cap the port and boom my motor dies. I set the idle screw to 2500 rpm and capped the ports I stay running but rpm drops to 1000 rpm and my idle mix screws don't do jack at that point . I have no clue what's going on help
Used I know bigger prob. I was using a 750 holly vac secondary but it was just running very rich and this little 600 when it's running still smells very rich
You are dumping fuel from someplace for some reason. What's the fuel pressure? Float setting? It would have to be rich to stay running with a huge vacuum leak
Well that's what I'm thinking how ever I need to find that out. Would a clogged jet dump that much fuel? I thought about getting a fuel reg and setting it at 5.5 lbs and see what happens
Check the air fuel screw tips. If they have been overtightened, the tips could be broken off in the seats. If they look fine and the regulator doesn't help, check to see if the power pistons are gummed and stuck up (just under the small covers next to the bowl vents). If not, you might have to just tear it apart, shouldn't need any gaskets if your'e careful. Make sure the right and left boosters are on the correct sides and all the air bleeds are clear.
the Edelbrock tuning book is available on line, great source of information. I buy them all the time, most problems are simple adjustments covered in the book.
Edelbrock is a simple carb. They like to ****k -n-span squeaky clean About 4.5 psi fuel pressure. If nothing is broken it should work fine. I wouldn't bother doing anything without knowing the fuel pressure
One more thing to check is the metering rods. I've seen a few people get frustrated and taco them trying to get them in.
A clogged jet would restrict the fuel and 4.5 lbs is correct. I run two 600 cfm Carters (same thing) on a mild 355 for the last 3-4 years, with no problems. Get the pdf file instructions from Edelbrock's web sight and get to sorting it out.
Have you checked the timing? What happens if you also cap the vacuum advance line any difference? Just an idea, but could be with the big vacuum leak there is not enough manifold vacuum to even operate the advance can, and then when you do cap it , it goes to full advance and if the timing was to fast to start with it advances it far enough to kill it. Or when fully advanced it could be shorting something in the distributor. Might not be at all related, just another direction to look.
Yea, 90% of carb problems are electrical in nature. Theres a little comment up there that two carbs, this Edy and a holly have been running rich.
Are you using a quadrajet type intake? Sometimes when switching to an edelbrock carb you need an adapter plate or they won't run correctly.
Alright guys here is where I'm at at this point. I bought a fuel pressure gauge hooked it up and well it broke and flooded with fuel so lol. I bought a fuel regulator and set it at 4.5. Next I tore the carb apart and found the float was set bad. I reset the float to edlebrock spec. The needles are good and clear, the air/fuel screws are nice and sharp on the end. I put it all back together and boom it works. now I have another small problem Now I'm getting 16 vac pressure . 4.5 fuel psi but this ****er is running rich, rich. Like headache in one min rich. I dialed down the fuel pressure to 3 but that did not help. P.s I'm runnin about 900 rpm. Any ideas Pss should have kept the holly
Tuning is a series of steps, you have to redo those steps . Its like a dance, keep after it. Bump your timing up to highest vac and that will require you to decrease your idle speed and turn the mixture screws. Repeat till you get her dialed in..
You can also use the vacuum gauge to set the mixture screws as well. I personally like to use my old dwell meter to read the highest rpm while adjusting but I do use both.
By now your spark plugs are fouled from all that rich fuel mixture. I don't know of a good way to clean up plugs that have been through all of this. Put a new set in before going any further.
The idle mix screws won't do a thing at that high of RPM. You have the throttle blades open past the idle slots or ports (whatever that are called on an edbroke carb). You are way past running on the idle cirquite. Have you checked to see if the choke is slammed shut when it does> if it is flooding real bad like folat stuck or **** in the needls valve or the chike is slammed shut then your vac ports hanging open should lean it out enough to run and with then closed it isn't getting enough air to mix with thre fuel. Check and make sure that is sin't flooding if you suspect that it is an induction related problem and not some other problem. That is where I would start.
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