I have a 340 four barrel Holly double pump , street cam, headers. The cam is nice and prominent at idle but when I put it in D or R it dies immediately. No loose hoses or vacuum ports. Tightened the intake and carb. After it stalls it will not start without priming the carb. Checked and it looks like it's getting gas. Plugs had carbon... Ideas?

What is your initial timing?
Does it change from N to in D?

what is your initial? ported or manifold? pull the idle mixture screws & blast the holes with a 3 second blast of starting fluid then replace the screws (count # of turns to lightly seated to easily return em to their original position). you might install a gutted PV so it's idling on the power circuit which MIGHT point to a vac leak. post how it goes.

I'll have to check the timing. I'll get my gun tomorrow and try it, Also I was reading about the idle mixture screws. I don't remember if I even set those when I installed the carb several years ago. I'll post something on this tomorrow

""I don't remember if I even set those when I installed the carb several years ago.""

For a tuning reference, tighten each of the metering screws clockwise until they "lightly" bottom out. Count how many turns it took for each one to seat and let us know what this was. Then take a permanent marker (any color will due) and mark each metering screw at the 12:00 position. Then turn each metering screw outward 2 turns (your mark will be at 12:00 again) if this is a carb that has 2 metering screws. If it has 4 metering screws, turn them out about 3/4 turns each.

This will be a good starting point and your previous metering screw position will be a good reference to help figure this out.

Looking at the picture, you've got the distributor vacuum advance line hooked up to the wrong fitting.
You've got it hooked to a ported connection.
You need to move the hose to the fitting under the float bowl.
That's manifold vacuum and where the hose should be connected.

Okay. I initially had 10 + degrees I'm guessing it was about 15. I couldn't see the timing mark. backed it off and the car was hard to start. I can't even check when the car is in drive because it dies then wont start. I moved the timing up and the car died I changed the vacuum hose per 340727dart. I set the idle mixture screws 1.5 out (I only have 2). I've been messing with it all afternoon. The car floods out when I try to start it again. I have to let it sit every time. When I installed the engine it ran pretty good some 6 years ago. I haven't worked on it since and would start it every couple of months. so it's been sitting. It would idle pretty good till it warmed however it would eventually die. I have my Challenger same thing it's been sitting . .. idles fine no problems. The Cuda has a pretty lopey cam and the four barrel ... I thought it was a 650 or 750.

I would suggest that since it has been sitting for so long, pull each needle/seat and clean them and then reset your float levels. You might have some crud in them causing flooding.
You may need to buy a dial-back timing light to be able to set a higher initial timing setting.

suppose to be hooked to the ported vacuum on the metering block.

Got it ! A little late to post but here it is. Checked timing, intake gaskets and bolts, carb gasket and checked to make sure the bolts were tight ... no signs of a vacuum leak. Hoses ... tried different connections... all looked good ... no change.
Finally I saw a post about the accelerator pump. Every time I checked for gas, I saw the familiar vapor coming out the carb. I thought it was working.... I looked inside and ... Wow ... the stream was pretty weak.I took the accel pump off ... it looked brand new... seemed to work fine, put it back together .... no change... took the squirter off... very carefully ... cleaned the holes worked the accel pump with it off... very little gas coming up ..... well , after a few more times playing with the pump I was getting a good amount of gas. reinstalled the squirter ... started it and it worked like a charm .... must wave been gummed up. I'll take it for a drive tomorrow..... Yes!

The accel pump does not effect the idle mixture until you step on the gas....so it shouldn't fix your problem....if the accel pump was gummed up so is the idle circuit and the rest of the carb, it needs rebuilding. I think your idle mixture is lean...and that's why its stalling.

Correct. Mopar dist. are on ported vacuum. Chevys are on manifold vacuum.
While idling in park turn the idle mixture screws in. If there is no change in the idle then the carb is not on the idle circuit. Need to back off the idle speed screw and probably advance the timing.

This is correct.

When the timing sees manifold vacuum you will never get it set properly.
Change the timing.
Engine speed goes up.
Vacuum goes up.
Timing advances.
Engine speed goes up.
Timing advances (too far this time).
Engine speed goes down.
Vacuum drops.
Timing backs down.
Engine speed goes up.
Vacuum goes up.
Timing advances.

See where this is leading?



Go to ported advance:

Change the timing.
Engine speed goes up.
Vacuum goes up.
Distributor doesn't care because it can't see vacuum until after you're on the throttle.

This ... especially if it's ethanol blended fuel.

Then his description of the cam is so vague , what does it have for a converter ?

What distributor is it and has it been modified if it is a stock MP distributor to limit mechanical advance with the higher than factory initial ?