Bronco dies after idling in park

[Bully Bob]

What are we going to do with you...?? :lol: :lol: :lol:

Actually at this point.., that's normal given you have a "rich" & likely "flooding" condition.

This all comes out the tail-pipe, & especially if there's any moisture (humidity)

This goo's up in the exhaust & spits out. This ALSO creates a "stinch" that sticks to your clothes & "nose-hairs" ...!!!

"..and after 7-8 min the engine turned off"

A few likely things as stated but one that comes to mind is, junk in the tank that gathers at the inside the tank fuel pick-up screen.

BUT.., more likely the carb flooding over & stalling the eng.

Have you pulled a spark plug to take a reading..? The plugs are always a "window" as to the condition/tune of an engine.

Unless the choke flap slammed shut again....

 

[Rons beast]

OK 73,

Here's the deal. everything sounds like there is a choke problem. As Bob said the black is carbon which will get heavier when the engine is running too rich. Also when the choke stays closed, the engine vacuum pulls more fuel out of the jets than it needs. the extra fuel washes the oil film off the cylinder walls. When you first start back up there can be an engine knock until this film is restored. This explaines your knock, stalling, carbon and hard restarting.

Try this. Get the truck a little warmed up. Remove the 3 screws on the choke cover and remove the choke. (There will be a small vacuum leak, but nothing to worry about at this time.) Leave the air cleaner off. Restart the truck, and be sure the choke is open. You sometimes have to put a screwdriver in the airhorn to hold it open when there is no choke spring. Back it out of the garage...not good to have it idle long inside.

With the choke open the truck should idle and not flood and stall. If this is the case, then you only need to determine why the choke spring is not opening the choke as the truck warms.

Check that the rod to the choke blade is connected to the left side of the choke pivot shaft. This means that as the choke spring expands, it turns the shaft clockwise, ( as you look at it head on). That in turn rotates the arm connected to the shaft clockwise, and raises the rod, which opens the choke.

You can carefully apply heat from a heat gun or "flick-a-flame" to the choke spring as it's laying on a non flamable bench or the garage floor. Heat should make the spring expand counter-clockwise.( as you are viewing it.) If that is not the case you need a new choke spring/cover. While the cover is off check that the small passage to draw heat in the choke horn are clear.

Hope this helps.

(BTW, Bob, I just went off the sticker on the side of the carb. It does look like a Motorcraft, but is listed as a Holley replacement rebuild?? IDK! :blush: )

Good Luck