76 Bronco won't start ... no fuel

[76BroncoTWJ]

Hi all, newb here.

I just bought a 76 Bronco. Been wanting one for years, so I'm pretty excited. The guy I bought it from said it hasn't been started in over two years.

I pulled the plugs and shot a little Marvel Mystery Oil in the cylinders, then rotated the engine manually to see if it would turn easy. It did.

Next I put a battery and a set of plugs in it, poured a few gallons of gas in both tanks because I don't know which is the main and which is the reserve, and tried to fire it up. No good. Not even a sputter.

Shot some starting fluid down into the carb and she wants to start, but as soon as you quit shooting the starting fluid down that throat, it quits trying to start.

Disconnected the fuel line from the carb and spun it over, no fuel.

Crawled up under it and disconnected the fuel line from the tanks to the fuel pump, and fuel comes out.

My first thought is it's a bad fuel pump, but I'm good looking, not smart, so I figured I'd ask some people who knew more about it than me.

My buddy who is a lot smarter than me says he wonders if the fuel prump just needs priming or something and wants to jack up the back of the Bronco so the gas has an easier run to the fuel pump so it won't have to work so hard.

I'm not so sure about that one.

Does anyone have any advice?

Thanks,

TWJ

 

[Explorer]

Never had to prime a fuel pump. Stick the outlet hose from fuel pump in a container and you should have fuel out if you have fuel coming to the pump. Fuel in, not out=fuel pump. No fuel in, work your way back to the tank. You can run the engine from a gas can and hose gravity fed to carb or fill the bowls thru the vent tube to get it to start and run, which you've already proved. Bad pump, clogged lines, clogged fuel sock on pickup tube are all common problems.

 

[gearida]

Do you have two tanks? There is a chance that the two valves are not in the correctly orientated allowing fuel to flow. Take the hose off of the tank and the fuel pump and blow air through to see if you have a clog. Feel the pump for suction and pressure as you crank the motor with the lines off and your finger on the inlet/outlet.

 

[76BroncoTWJ]

Thanks for the responses, guys.

When I disconnected the line that runs from the tanks to the fuel pump, fuel came out of it (but not much).

I'm at work now, and was planning on disconnecting the fuel line from the output side of the fuel pump when I get home to see what happens. It's getting no fuel at the carb at all, so I figured if fuel comes out of the pump, then that line must be clogged.

Is it the forward tank, or the rearward tank that is the reserve?

Also, how much fuel should be coming out of the fuel line from the tank(s) to the fuel pump when it is disconnected?

And finally, I called the guy at AutoZone about a fuel pump for this baby, just in case. He said it was 90 bucks. Seems a little high to me, and he sounded like the same guy who said he'd never heard of Marvel Mystery Oil when I went by there yesterday. I don't have too much confidence in him. Does that price sound right?

Thanks again,

TWJ

 

[JEFF76P]

Your forward tank is reserve and the control for switching the tanks is directly under the drivers seat. also change your fuel filter, I did that on my 76 after sitting for a year and it started right up.

 

[76BroncoTWJ]

Jeff,

Thanks for the response. There's a fuel line of bent tubing that runs from the fuel pump up to the top of the engine, then a piece of fuel hose that runs from that fuel line to the carb. That hose has a small crack in it, and there is no fuel filter in it. My plan is to replace that fuel line and put a filter in it.

Is that the fuel filter you're referring to, or is there another (or others) under the Bronco? I looked while I was under there, but didn't see any.

 

[g8rb8t]

Fuel pumps are around $20 from Rock Auto. My fuel filter is threaded into the carb and I also have an inline one (aftermarket) before the fuel pump...

 

[302fix]

...then a piece of fuel hose that runs from that fuel line to the carb. That hose has a small crack in it, and there is no fuel filter in it...

That's probably the problem. There could be a screw in filter at the carb. If not you need to put one somewhere before you start running it.

Might not be a bad idea to pop the top on the carb to make sure it isn't 'gunked' up.

 

[Viperwolf1]

Please don't crank the engine with the fuel line disconnected. You can look down the carb throat while moving the carb linkage to see if there's fuel.

 

[JEFF76P]

The fuel filter screws into the side of the carb. and the rubber hose attaches to to the other side of it.

 

[76BroncoTWJ]

After looking over the fuel lines a little closer I discovered that the rear fuel tank is not hooked up only the front one. I also did not mention earlier that the bronco has a edelbrock carb on it. Yesterday i replaced the fuel pump hoping that would solve the problem, it did not. So today I removed the fuel tank and discovered that the pick up tube filter was clogged with alot of gunk and the tube it self had quit a bit of obstruction. My next step is to see if the auto parts store carries just the filter for the pick up tube or if I have to replace the whole unit. Then I will be ready for reinstall and try again. Thanks for all the help and I will keep you updated.

 

[DirtDonk]

If they can cross over Ford part numbers, that "sock" filter is a D1AZ-9A011-A.
I'm not sure if that part number is for each filter, or for the pair-pack I bought, but that's the number on the package.

In case they go by description instead, Ford made two sizes for the different applications. The Early Bronco one is a 5/16" fitting, while the full-size trucks got one with a 3/8" opening.

Hope that helps.

Paul

 

[DirtDonk]

Oh, and while I fully support Viperwolf's statement to not try to crank the engine with the pump line open, I don't always do as I say either.
I did have one pump that responded to priming once and it didn't pump an ounce for quite some bit of cranking. So I pulled one hose end off, put my finger over the opening while someone cranked away with the starter for a moment. Worked like a champ right after that.
Absolutely no idea why it helped, but like putting your finger over the hole of a trigger-spray bottle to get it to pump up sometimes, it seemed to work.

In order to avoid that hassle here though, I'd just fill the carb with fuel so that the engine will start and help the pump rolling along that way. Usually (but not always), before you've used up the fuel in the bowl, the pump is happily pumping away and you're good to go.
Much easier and safer than the aforementioned "priming" ordeal. And it only takes one person too!

Paul

 

[windsor]

(((((((And finally, I called the guy at AutoZone about a fuel pump for this baby, just in case. He said it was 90 bucks. Seems a little high to me, and he sounded like the same guy who said he'd never heard of Marvel Mystery Oil when I went by there yesterday. I don't have too much confidence in him. Does that price sound right?)))))))

Never have much confidence in someone working at autozone. (IF YOU WORK AT AUTOZONE AND ARE A MEMBER OF THIS SIGHT I AM SORRY AND YOU ARE THE EXCEPTION!!)

 

[76BroncoTWJ]

Paul thanks for the info I went to autozone and orileys today and neither of the stores had a clue what I was talking about. I found the sock online last night for $10 and will probably order it now. Thanks for all the info and I hope to have this thing fired up tomarrow.

 

[76BroncoTWJ]

I mean Dirtdonk not paul sorry.

 

[TBS-POPS]

you should consider droping and flushing both tanks since you have found so much crap in and around the pick-up tubes and lines. might be worth it in the long run.

 

[76BroncoTWJ]

Thanks TBS I actually did that today. Today was in some ways a good day. I actually got the bronco started. I rigged up a gravity fed fuel line and it started. While running the fuel pump must have primed and it started spurting fuel, so I reconnected the fuel line. This was semi successful. The bronco started 8 or 10 times, but would not keep running. When I would give it gas it would die. I think it may be a problem with the carburater. This truck has not been ran in about 2 years so what would be my next step?

 

[Viperwolf1]

Thanks TBS I actually did that today. Today was in some ways a good day. I actually got the bronco started. I rigged up a gravity fed fuel line and it started. While running the fuel pump must have primed and it started spurting fuel, so I reconnected the fuel line. This was semi successful. The bronco started 8 or 10 times, but would not keep running. When I would give it gas it would die. I think it may be a problem with the carburater. This truck has not been ran in about 2 years so what would be my next step?

I'd rebuild the carb next.

 

[76BroncoTWJ]

Ok I guess I need to slow down. Before I rebuild the carb I need to figure out why I am not getting fuel to the carb from the fuel pump. I have checked all the fuel lines and replaced all the rubber lines with new. I also installed an inline filter between the fuel pump and carb. My thoughts were with a clear fuel filter I would be able to tell if the pump was pumping fuel to the carb. That never happened. The only time I knew it was pumping fuel is when I rigged the gravity fed fuel line to the carb and when the bronco started I placed my finger over the out line of the fuel pump and I could feel pressure(almost like it was sucking), then it seemed to prime and fuel started spurting out. So then I disconnected the gravity line and reconnected the out line and no more fuel. I am about to give up and go with an electric fuel pump. Any ideas would be appreciated.