Help !! Running super rich.

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71_dart_swinger

71_dart_swinger

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I know it’s a truck.. but.....
I took the 2bb off of my 360 and put a low deck weiand single plane on it with a brand new Holley 600. Runs super rich. There’s no vacuum leaks? I’ve changed the intake gaskets 3 times. No leaks . I’ve put on 2 different brand new Holley 600 vs. also edelbrock 650 new to try. Starts to idle pretty high and runs super rich. Can’t find any leaks. New OE fuel pump. Runs horrid. Barely drivable. Runs a tad better with an old Holley 750dp VS on it. I’m at a loss. The plugs are immediately fouled. ? Ran great with the 2bbl. Just wanted a bit more pep I know. Single lane isn’t ideal. But it’s what I had. I’ve had all the nipples on carbs capped and hooked up to vacuum advance, pcv, and booster. All run exact same. I know it’s not the carburetors. There’s no change with them when I play with the idle screws. I lowered float levers. Adjusted choke. What else is there ? Thank you guys
 
A vacuum leak would likely cause the opposite effect, running lean. Where is the timing?

Multiple carbs ?? running out of ideas

What is "rich?" You sure it is not oil? Maybe the ports are leaking from the valley into the ports, causing oil to get into the intake stream
 
Indeed. Where is your initial timing?
 
Needs more timing if it doesn't do anything with the idle screws throttle blades are past the transfer slots.
 
Look down the bores with the engine running at idle if you see fuel dripping from the boosters you most likely have a blown power valve.
 
There is no fuel dumping or dripping in as I can see looking in the top while running .
It’s rich because there’s black smoke and it’s burning my eyes lol. Loading up real bad. I don’t think it’s a power valve issue as it’s literally had two brand new out of the box Holley on it and my old DP.
I have not touched the timing. ? Will have to check in the morning. Thank you guys so far. I will keep you updated.
 
If the timing is still set to stock specs, there's one issue. Check it and let us know.
 
RustyRatRod said:
If the timing is still set to stock specs, there's one issue. Check it and let us know.
Click to expand...
It is stock because it just did smog back in sept. (I’m in ca). It’s now a 1974. Shhhhhh. Lol. But it’s so rich I don’t think timing is the issue. But will for sure advance it. Been wanting to anyway
 
71_dart_swinger said:
It is stock because it just did smog back in sept. (I’m in ca). It’s now a 1974. Shhhhhh. Lol. But it’s so rich I don’t think timing is the issue. But will for sure advance it. Been wanting to anyway
Click to expand...

That will just be your little secret. Timing is very likely the issue.
 
A blown PV does not cause boosters to drip. A popular misconception.

Boosters will drip [ at idle ] for two reasons: carb is flooding &/or t/blades open too far at idle.
 
Stock specs? That's the problem! We used to do emissions where i am but only on obd2 now, when would take our cars in they would barely run with stock specs and were total dogs.
 
Listen to the old farts here about timing. After any changes to an engine, it's always good to check timing & idle, not to mention idle mixture.
 
Im not positive, but you swapped from 2bbl to 4 bbl.
timing may be the common issue here.
 
Is your throttle cable adjustment limiting the return of the primaries?
 
Bewy said:
A blown PV does not cause boosters to drip. A popular misconception.

Boosters will drip [ at idle ] for two reasons: carb is flooding &/or t/blades open too far at idle.
Click to expand...
"Blown?" If you mean "blown" as in the diaphragm is ruptured or the gasket is torn, the thing leaks fuel directly out of the fuel bowl and right into the intake.

But you won't (likely!!) find THREE blown power valves in three different carbs!!!
 
67Dart273 said:
"Blown?" If you mean "blown" as in the diaphragm is ruptured or the gasket is torn, the thing leaks fuel directly out of the fuel bowl and right into the intake.

But you won't (likely!!) find THREE blown power valves in three different carbs!!!
Click to expand...
And as the OP said he tried 2 Holleys and 1 Edelbrock. The Edelbrock doesn't have a power valve to blow out. If fuel dribbles out of those it would probably out of the bowl vents because of a needle/seat/float or float adjustment issue. To @71_dart_swinger , did you by chance change the fuel pump? Excessive fuel pressure will cause a rich run issue. You don't need any more than 5#.
 
^^And I almost mentioned "dirt"^^ If the tank/ fuel system has example, fine rust, maybe it's pumping in through the carbs and the needles/ seats are leaking.......................................
 
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