I have a 84 F350 with a 460 with a 4 barrel carb.when I drive it a long a mount of time and turn it off it floods itself out making it hard to start again unless I let it sit for a long period of. Last week I was hauling load a hay and drove it for about an hour and turned off the truck to load hay and when I went to start it it acted and smelled like it was flooded. I finally got it started and drove about for about 40 minutes when it died on me and smelled like it had flooded itself out.I waited about an hour and it fired right up. I drove it 4 miles and it quit on me again. Waited another 45 minutes and it fired up again and was able to travel the 2 miles home without any problem. Any idea on what could be causing this issue? It has an external electric pump mounted on the frame with 5 to 9 PSI. I have heard of people having issues with heat by the carb causing it to flood itself out. Is this true?

 

Someone with more experience with this truck might chime in but I would suspect/inspect the ignition, is there spark at the plugs when the truck cuts out/won't start?

 

I have spark and just replaced the Solenoid on the driver side. I can try to turn it over but it only starts if I let it sit for a while.

 

These are classic symptoms of a failing ignition module.

I know you say you have spark, but im pretty certain that it's the DSII module on the driver's side inner fender.

No ignition will always make it smell flooded because the fuel isn't being burned.

Does the truck pop on deceleration?
Is the powervalve blown?

 

If you want to check for flooding, get a flashlight and be prepared to take the aircleaner off. Run itlong enough for it to mess up, and as soon as you turn it off, don't wait go ahead and take the aircleaner off, and then climb up on the bumper and shine the flashlight down the carb throat. If you see fuel dripping into the engine, that's your problem. Your float levels are set too high most likely. Different fuel pressure can affect the float levels.

If you have the original style holley 4bbl, I am not sure if you can adjust the floats externally without taking the carb off. On a aftermarket holley you can adjust the floats without taking the carb off or apart.

 

The stock 4180's are adjustable.

Remember the screw is the lock and the nut is the adjustment.
Clockwise is lower.

 

Yes and no, sort of. There's been many discussions here about heat-related carb problems. At one point, a vague consensus was the problem was caused by heat, but the exact mechanism was still unknown. I'm not sure it's flooding in the strictest sense, meaning liquid fuel collecting in the intake. My hunch is the fuel percolates and gets foamy. There are several competing theories we have, but the upshot is if the carb gets too hot, the fuel mixing and delivery is affected.

My '84 351W 2bbl, for example, gave me fits several years ago. Hot restarts were always a problem, but it was manageable. Then I had several instances of the engine quitting shortly after working hard, when just loafing along. In all cases, it started right up after sitting for about 45 minutes, just like you've described. My overkill fix was to make some mods to keep the carb cool, and the problem has never returned, even under the exact circumstances.

I also found my engine is VERY sensitive to the brand of fuel. I almost always run Chevron, and never had any problems. In all cases where the engine died, I was running 76. I have another vehicle (a '63 ****** with a '73 Chevy 350) that is über sensitive to the brand of fuel. I have not modified it yet to keep the carb cool. I've found if warmer than 85 degrees, it won't run reliably on anything but Chevron.

So here's some quick and cheap troubleshooting you can do. Try a different brand of fuel (Gonna recommend Chevron again) and see if your engine now behaves. Duplicate the fault conditions as much as possible. You were hauling hay, which meant it was working hard. Don't make any adjustments or change any parts for now. If the problem changes, whether better or worse, you know it was fuel-related. If no change, then the problem lies elsewhere, such as with the ignition system, as previously suggested.

 

Thanks guys for the help. The Carb is carter so I am not sure if I can adjust the floats from the outside or I will need to remove the carb. Any one know anything about carter Carbs? I will check to see if fuel is running down the carb. What are some good ways to keep the carb cool. Currently I am using the stock air filter pan that has the spout pointed toward the fender but not sure how to get more cold air through it. Thanks again.

 

AFB or AVS?
Can you post a picture of this carburetor?

These carburetors can be more sensitive to fuel pressure, but none of this explains why it only dies when hot.

There is a plastic accordion piece that should extend the snorkel to the radiator support, between the battery and the radiator.

 

As previously mentioned, you'll want to get that snorkel tube that connects to the spout on the air cleaner. Instead of drawing warm air from under the hood, you'll draw cooler outside air.


I'd also suggest adding a heat shield sleeve over the fuel lines under the hood. This will help keep the fuel from picking up too much heat on the way to the carb.


Details of my travails and mods in this long thread, especially in post #6:


https://www.ford-trucks.com/forums/1...e-vs-heat.html


Before going too deeply down that rabbit hole, I'd suggest following the other advice to check the fuel pressure at the carb inlet, etc.


As far as cooling "mods", be careful because it's easy to do more work than really necessary. I think the snorkel tube and heat shield are a good start. Most of the other stuff is a lot of work, and likely isn't needed in most cases.


What do you think of trying a different brand of fuel as an experiment?

 

Percolation is the correct term. What happens is just like how a coffee maker works. The fuel starts to boil in the fuel bowl. This creates bubbles that push their way up the passages to the venturi. While they are making their way up and out, they are pushing fuel up and out the venturi at the same time. This makes the venturi "drip" into the intake when the engine is shut off.

Normally, only the low pressure from the venturi as the engine is running pulls the fuel up into the venturi.

 

The Carb is a Carte ABF competition. Below are some images of the engine and carb. changing fuel is something I am going to try. I took the truck for drive today with out any load and drove it for about 20 minutes and had no problems with it. I was running the same fuel and have not done anything different since since it was having issues. Only thing was that it was not under any load. Anything thoughts?
This truck is work truck that hauls hay through out the year and also our 24ft camper. Hoping to get this truck running strong and dependable.

 

Well, if it's behaving anything like my truck had been, it would only act up when the truck was fully loaded and the engine had been working hard. It could run all day when lightly loaded without issue. High altitude and high air temperature made it worse, too.

 

I haven't read through all the responses so maybe it has already been mentioned, but if it turns out to be a heat related problem with the carb, you can buy thick phenolic spacers to go under the carb to isolate it from the heat of the intake.

 

That's why I asked for a picture of the carburetor.
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And it appears that the EGR spacer is missing because the PCV is plugged directly into the carb base.
I wonder how the EGR port is blocked off?

A phenolic spacer could help a lot, because if it is the stock intake exhaust gasses are flowing directly beneath the carburetor.