Short story: I need a vaccuum diagram for a California bought (Emissions and such) 1972 f250 360 auto trans with a holley 500 carb. And if you know how to hook up the auto trans kickdown on carb I'd appreciate any info.

Long story:

So I inherited my Granny's 72 F250 with a 360, auto trans, 2 wheel drive. It's the best shade of green I've ever seen. It sat for 15 years or so....

I rebuilt the carb. New gas tank, cleaned fuel lines. New spark plugs. New distributor cap. New wires. New fuel filter and pump. When I got the truck the vaccuum lines we're disconnected. So right now, when I try to start it it just floods gas out the top of the carb...seems to have no spark.

So plan at this point is to switch to electric ignition and ditch the points. But I also need the vaccuum diagram.

 

easiest way to hook Trans kickdown on a holley is get the Lokar cable kit . I messed with my original rod set up for days and never got it right . 30 minute install with lokar and it work perfect .

 

72 in California you don't have to have all the original smog BS .
If you are not going for Original just remove all but PCV and vacuum advance to Dizzy.

 

Thanks Mike. For the PCV that's the oil cap thingy coming off the valve cover? I plumbed that to the large port on the back of the carb. The advance comes off the distributor cap? Then plug all the other vacuum ports?

Thanks for the tip on the kick down. Much appreciated!

 

If you have gas coming out of the top of the carb the float is stuck. It will never run if the engine is getting flooded with fuel. Get the carb right first and then you can tackle the distributor.

 

Bet $100 the float spring is not attached right...

 

No spark check voltage going to coil should be around 6-8v with key on open & close the points with a plastic handle screw driver should get a spark at when opening & closing the points. If no spark then replace condensor.

IF no voltage at the coil + side check ign switch as they can go bad or the plug on the back of it..
Also time to buy a shop manual for your truck it can help you more then we can..
Orich.

 

No smog inspections in CA prior to 1976.

1968/72 F100/350 360/390 / 1969/72 F100 302:

Smog valve fits into a rubber grommet on the right (passenger side) rear of the valve cover.

Left (drivers side) valve cover at the front: Oil cap has a hole in it, rubber grommet fits into hole, plastic elbow fits into grommet.

PCV hose slips onto the elbow....attaches to nipple on air cleaner or to nipple on carb spacer plate.

 

Holley 500 CFM 2V model 2300 carbs come from the factory with a "center hung" float and bowl. I think either the float is bad and has gas in it, you used an aftermarket kit, or you didn't pre-set the float adjustment. I have run across aftermarket needle and seats that do not shut gas off when they need to. Buy a genuine Holley needle and seat part number 6-504. If it needs a float the brass part number is 116-2. Or my preference would be a Nitrophyl made one part number 116-3.
To adjust float level, flip the bowl assembly upside down. Screw the needle and seat clockwise until the float is level. Then lock the needle and seat in there with the nut,screw, and gaskets.

 

I think you nailed it. After watching a couple youtube videos i mucked with the needle and seat and float levels. Now she fires up and will run about 5 seconds then carb floods with gas out the vent tube. This makes me think the float has a hole and is sinking (will test in a bucket today). But what about the spring on the float? How is that supposed to be connected? Pretty sure the timing is way off too. Need to invest in a timing light.

 

Probably don't.need a bucket.... after removal, just shake the float to determine if any fuel got inside.

The float spring counteracts the float action... keeps compression on the float so it doesn't bob/oscillate. And the needle dangles.....

 

Okay float was good. Stared at it and the needle and seat for a long while to see how it works. Bent the tab on the float a bit so that it engages the needle sooner. Even with the needle and seat screwed all the way down so the locking nut barely had any thread on it the float still wasn't getting high enough to engage the needle and stop fuel delivery which caused the flooding. I compared the needle and seat to another from a rebuild kit and they're identical so I'm assuming its the right part.

Might have bent the tab too far. Got a big backfire (just smoke and loud pop no actual fire) out of the carb. Thinking I need to get more fuel in there now and adjust the float needle up a ways. Also thinking timing is off a lot. I don't know much about the engine other than it was supposedly rebuilt, may or may not have an RV cam in it and may or may not have been turned into a 390. There's a mark on the harmonic balancer which I assume is TDC. There's also a matching mark on the distributor. There are no lines on the harmonic balancer to measure degrees or anything. Just this one hand drawn line.

So my questions at this point are:

1. Is it possible the timing is so far out of wack that it won't start? Pretty sure I've got the firing order and plug wires setup correctly. I did get it to run for about 10 seconds at one point before it flooded out the vent tube. Sounded really good too. Sure a bit rough but still awesome.

2. Is it more likely I just don't have the needle and float squared away yet?

3. As I continue to screw around with this thing is it better to have the vacuum advance on the distributor hooked up to a vacuum port on the carb? I'm looking for the simplest setup with the least number of variables to get it running and then I can dial it in from there. Just wanna make sure I'm not sabotaging myself from the get go.

Thanks for all the help. These carbs seem so simple but good lord they're complicated little beasts.

 

Question 1: Yes... definitely. Without benefit of a light, look for a scribe line or mark on the distributor body a previous owner might have made to indicate a decent starting position. It may not be correct as such, but it would have ran like that. Beg borrow or steal a timing light.

Carbs are tricky, but once you understand the basics they aren't bad. And there's a ton of information available for download, at no cost. Charts, manuals, instruction videos, whole websites devoted to a single model of carburetor with archived forum posts going back 20 years... Effective use of source material is your friend here. Spend a couple hours reviewing the information and specs, it will go a long way to getting your engine to purr reliably.

 

Thanks very much. This forum is awesome. So dumb question. What does the line on the distributor indicate? It's there and matches the line on the harmonic balancer. What do you mean by starting position? Sorry I'm learning as I go here. And oh by the way I switched it over to electric ignition in the distributor over the weekend. That fixed an overall no spark issue.

 

Well, let's say the truck was running good, but you had to mess with the distributor for some reason or remove it. Take a sheet metal scribe or maybe a sharpie and mark a line from the distributor body to the engine. That way it can be reinstalled in the exact same position as before. That way the timing will not have changed, or it will be very, very close to what it was before. It doesn't take much for the distributor to be off. The width of a pencil line is approx. 2 degrees. So just dropping it in wherever, can mean the timing will be way off, and will not start, or won't idle.