I picked up a bronco ii a few weeks ago that would not stay idling after it warmed up. I put some sea foam in it and cleaned the throttle position sensor (feedback carb). It still wouldn't idle. Miraculously after letting it sit a few days it started idling and it ran good. The next day I went to drive it and it was blowing brown smoke everywhere and was sputtering bad. I noticed the choke wasn't opening and the electric solenoid was not getting power. I ran a hot wire to the solenoid and determined that it does work. While my choke was not opening I flooded out the carb bad and noticed I also got gas in my oil. I think the whole problem I had was centered around the choke problem. Now my questions I upward you can answer.

Where should I wire the electric choke in?
Could a closed choke make the gas enter the cylinders with continous starting and stalling?
Is there anyway to check for a faulty float?

Thanks for any help!!

 

What year is the truck, what engine and what carburetor? There's limited help anyone can provide without knowing what you're working on, but in general:

(1) The factory electric choke assist goes to the stator terminal of the alternator.

(2) All the choke does is enrich the air/fuel ratio in the atomized combustion mix; it can't cause liquid fuel to flow into the cylinders. Only a stuck float or blown power valve can cause this (or something catastrophic like a cracked throttle body). However, a stuck choke (closed when warm) can make the engine run rich enough that it will stumble and stall when warmed up. That's definitely possible.

(3) Depending on what carburetor this is, you can run the engine with the air horn removed and watch the float regulate the fuel level in the fuel bowl, just like a toilet tank. Generally if the carburetor is dumping fuel out of the bowl vents, then the float is stuck. Varnish and other junk in the needle seat is the most common problem for the float; it keeps the needle from seating, and floods the carburetor.

 

I am working on an 85 bronco ii with the 2.8 liter V-6. The carburetor is a 2 barrel motorcraft feedback carb. Thanks for that information I thought maybe the choke was causing it all that would have been easy. So should I do a complete rebuild of the carb or just clean the float?

 

If there's an issue with the float sticking, then the carburetor should be rebuilt. Like the old saying goes, "if you only fence three sides of the pasture, the cows will wander out eventually."

Is the choke even opening? If not, you can try forcing it open when the engine is warm (when it's stumbling) and seeing if the idle improves. If so, then the choke is related to the issue. Either way, if the choke's not opening, you'll want to address that too.

 

When the engine was running u opened the choke and it ran much better. I researched the symptoms of a faulty power valve and it listed black smoke from the exhaust and the truck was definitely doing that. I have always thought of carburetor rebuilding as a daunting task, but it looks like it is what I have to do. Is the power valve included in the rebuild kit? I'm gonna start the rebuild at the end of the week is there anything I should know before I start? By the way thanks for the help Its actually my girlfriends truck and I'm trying to get her up and running.

 

No problem. If the choke is stuck shut, however, that's not something that a rebuild will solve. The rebuild will only be necessary in my opinion if the power valve is blown or the float is stuck. Try and fix the choke problem first and see if that fixes it (meaning if the engine will stay running and stop dumping black smoke). The choke opens by way of heat. Check out the following thread:

https://www.ford-trucks.com/forums/8...-answered.html

Note, however, that that writeup was geared toward earlier stuff; I'm not sure what would have changed by '85. I was surprised to hear that this was an '85; I didn't know the Motorcraft 2 barrel carburetor was used that long. It makes sense it would be a feedback carb, at least. I had an '88 Ranger with a 2.9L V6 but it was fuel injected. My buddy had a Bronco II of the same year at the same time I had my Ranger; it was a cool truck.

To answer your other question, yes, the power valve is always part of a rebuild kit. The most crucial part of a carburetor rebuild is the cleaning phase. You'll want to soak all of the metal parts in the gallon can of carburetor cleaner for at least an hour; this will eat away all the varnish. The can (available at parts stores) comes with a dipping basket. When you pull the parts out, spray everything down with a can of carburetor cleaner spray. I usually do this in three sets: throttle body, air horn, and then all the small parts at once. Once everything is dry, you'll want to run compressed air through all the tiny passageways in the carburetor. Make sure you wear goggles for all of this. Don't get carburetor cleaner on your hands or breathe any of it; it's nasty stuff. Only soak metal items. Things like the float and the choke do not get cleaned. Everything else gets thrown away and replaced by the kit.

A few other notes, carburetor rebuild kits don't always come with the gaskets needed underneath (like the base gasket). Don't throw anything away until you're sure the rebuild kit has an exact replacement (some pieces get reused). Just take your time and keep track of everything; it might help to take pictures with a digital camera as you go, so you can remember how things went. The kit comes with a diagram that is numbered in logical steps. If you have ever worked with model cars, etc, then it's not much different. I rebuilt my first carburetor in my college dorm room.

That's a good start; but I'd still suggest making sure that the choke is not the issue. You need to fix this first by making sure the choke opens as the engine warms up. If the engine is still flooding, stalling, and blowing black smoke with the choke open, then you should check the idle mixture. If neither of those solve the issue, then a rebuild is the next logical step.