Hey guys very new here and frankly quite lost as to where to go from here. I got my 1984 f-150 351w OH about a month ago and have been tinkering here and there.

Yesterday I replaced the oil, read on here to go for 10w and not 5w (my inbuilt oil sensor often said pressure was low) well after i went for a drive and she drove great but stalled out once. Spent the next 6 hours looking for a fuel filter to replace, could not find an inline one, i have a 4bbl 50174 carb that has the fuel lines go directly in to the carb with no bolts to unscrew to find where little bronze filter inside the carb would be. So in an effort to see if i could see the filter from inside the carbs fuel tank i removed the 4 screws on the front part of the carb and looked around but couldnt find anything. It was difficult to get back on and I am wondering if maybe I messed up a gasket. I looked somemore and figured hell if i cant find the filter lets replace the pump thats only 20$. So to replace the pump i had to remove the oil sensor, also figured what the hell ill get a new one of these for 20$ too since i have it out. I put in the new oil sensor and fuel pump (mechanical) and the truck wont turn over.

I also replaced the throttle cable so figured I couldve flooded the engine doing that so i waited an hour. Came back out and she started up and sounded fine. Backed up to go for a ride and oil pressure hit max, and the engine died. Ended up barely being able to turn it around and get it back in the garage sputtering the whole way. Let it sit overnight, went out to start it again, had some trouble but got it going oil pressures maxed out and within 3 minutes noticed white smoke coming from the air filter, removed it and saw the carb bubbling gas out the top as the engine sounded worse and worse. Im leaning toward maybe i messed up my carb and getting a rebuild kit and replacing all the gaskets. Just dont wanna waste the money and new to this sort of thing. Appreciate any help.

 

Welcome to the forum. Congratulations on your new truck.

Don't panic over the present situation. Sounds like some new faults were induced. You'll need to revisit and correct those issues, preferably one at a time.

Let me make sure I understand the timeline correctly:

Truck is new to you, apparently runs okay. Oil pressure reads low, unknown if actual low pressure or just indication.

Changed the oil, still runs great, but stalled once for reasons unknown.

Took carb apart partially and reassembled. Now runs poorly.

Replaced fuel pump. No change.

Changed oil pressure sensor. Indication now reads high.

Does that sound about right? Not trying to bust your behind, but the first thing I'd suggest is stop throwing parts at the truck. If a new part is bad from stock (sadly, not uncommon), it can be a troubleshooting nightmare, especially if multiple parts were changed at the same time. Whenever possible, it's best to change one part and test it before moving on to the next.

It definitely sounds like something went wrong when you had the carb apart. To go back over your work, you may find it easier to remove the carb and do any repairs at your workbench.

 

Thanks, ive used this forum for a few other repairs. Been a lifesaver.

That time lines pretty close. But I messed with the carb, replaced the fuel pump and oil sensor before testing how it ran. So im unsure which of these for sure is causing my issues. Yeah this was a big lesson for me learned about taking projects one at a time. I was leaning toward the issue being the carb because the gas bubbling out the top. The fuel pump and oil sensor seemed pretty straightforward and nothing is leaking with them. The thing that confused me was the oil pressure being so high but I guess these could be unrelated.

Anything I should look out for or be careful about when removing, looking at the carb?

 

That is a holley factory carb. Getting the old gaskets off is a real pain. If you go at it and scrap hard with a scraper or razor blade, you risk damaging the carb gasket surface. The best way is to take the carb apart and buy a gallon can of carb cleaner at the store, and soak the pieces. It will soften the old gaskets and make it easier to come off. If you just want to replace what you took off, then try to soak the gasket in brake cleaner and see if you can get it off.

Your main problem sounds like a piece of dirt got stuck in the needle. The kit will come with two new needles and seats. This works just like your toilet at home, it stores fuel in that chamber and the float cuts the fuel off when it gets to the correct level. Yours is not cutting off. That is also why it's important to have a clean fuel filter. Since you have a factory setup, it will have a filter somewhere. I will check to see where it is on your truck.

 

I believe #9155 is the fuel filter. If this does not look like your setup, then someone has swapped to a aftermarket carb and you will have to go to plan B for a fuel filter.

 

On your carb rebuild you might be able to use less carb cleaner than a gallon. I take apart everything and soak it in carb cleaner but I put the parts in zip lock bags. Pour in enough cleaner into the bag so that you can fully soak the part after purging out the air and zipping up the bag. As a precaution place the bagged parts in a larger container in case of spills or in the case the cleaner eats through your bag. I soak the parts for days if I have time, 24 hrs minimum.

When the gasket surfaces are clean and all surfaces are clean I use compressed air to blow out every hole, passage and jet you can see.

 

I might get crucified here but i'll throw out a suggestion. When faced with a 40 yr old carb with unknown history (and some other things in life that were using up my time) i decided not to roll the dice that i could teach myself carb rebuild basics and do it right the first time.
I did some research here and found the guys at national carburetors in FL. I removed my carb, drained the gas, packed it up and sent it off to them w the printout from their website. A week or two later i got it back and it looked new. hooked it up, added some fresh gas and she cranked right up. Lots of time and energy saved.....the trade off is that it was more expensive than a DIY. I dont know how urgently you need the truck running but as i get older and life, kids, work, weather, politics, funding for NASA, **** poor football from the NY Giants, broken sunglasses, boat trailers, stubbed toes and whats for dinner get in the way, i found that this was the best route for me.
Good luck and cheers.

 

Yep, if you're that busy you don't have time for carb rebuild. I've always been afflicted with more time than money...that keeps me curious. Especially at today's mechanic rates!

 

A Holley carb has got to be one of the easier one right up there with the Carter v1 that is on my 300 six motor.

Now on the fuel out the carb and the new fuel pump.
It could be what you did to the carb or the new pump or both!
Yes something like gasket got in the needle & seat of the float so it will not seal or the float is hanging up so it will not close the needle & seat.
OR
The fuel pump is putting out to high of a pressure, dont think it can there have been a few posts on the forum and I had ti happen to me on a non-Ford.
Pump started leaking, car is only started to move around as I work on it so you get a replacement and all should be good .............. WRONG!
I start feeling wetness on my face as I look over the gauges and my son yells shut it down! Said fuel is coming out the carb float vent tubes big time.
Put a fuel psi gauge with a Tee and when running I was getting 18 PSI before I shut it off.
Returned the pump for a different brand and this one put out the 5 psi like it should. Again others has had the same issues with motor driven fuel pumps.
So I would also check the fuel pump psi to make sure it is around 5 psi. before going to crazy on the carb rebuild
Dave ----

 

+1 on that! When we DIY guys say we "rebuilt" a carb, what we really mean is we took it all apart, sprayed some carb cleaner in there, lost some little pieces, reset the float level, and put it all back together with new gaskets. It's roughly akin to replacing some gaskets on your engine and calling it a rebuild.

Sometimes the home "rebuild" does indeed work, such as if the float valve needed some love. But in many cases, it doesn't do much of anything, with a massive potential to make it worse.

After three "rebuilds" over the years on my truck's carb, I broke open my Scotsman's wallet (screams when opened) and purchased a remanufactured unit. It was like night and day. No comparison.

There's typically no harm it attempting a "rebuild" yourself, especially if you recently caused a problem and are now able to find/fix it. It was running okay before tearing the carb apart, right? Maybe not perfect, but at least adequate. With any luck you could get it back to that condition. But if there's any doubt, don't be afraid to go the reman route. It's not like we're going to take away your man card.

 

Does anybody know how the vents are arranged on this carb? It has two float chambers, right? Is it a common vent for both sides, or separate vents?

If separate, and only side is leaking, that would indicate a problem with the respective float valve. If separate and both sides are leaking, that would be excess pressure from the new fuel pump.

None of this matters if there's a common vent.

 

Two separate vents. One front, one rear.

 

Hey guys appreciate the help all around. I finally have some time coming up where I am going to do the carb but I am running into an issue. I have no idea how to get two of the hoses out of it. I can get the fuel line, off and the bolts off. But there are 2 hoses running in the front and back seemingly with no threads. The hoses have a rubber part with a "****" of some kind but I cant for the life of me figure out if its a way to disconnect the lines. I will attach picture below.
Anyone have ideas on how to remove the circled hoses in the pictures below so I can pull the carb out?

 

Just pull them off. That steel line coming out of the carb is just a nipple for the rubber line to slide on to.

 

There is a short rubber hose between the metal nipple and the black / white plastic part.
If the hose is rock hard I would use side cutters to cut the rubber off each nipple.
Just be careful not to cut the plastic part.

Can also try cutting it witha razor
Dave -----