Bronco starts but won't run...

[film915]

Having a little issue with the truck today... was driving around all happy, everything running as it should, when she just suddenly just shut down. Pulled over and tried to start it up again. She seems to fire up just fine, but only idles for 3-4 seconds before dying. If I try to give it gas when it's idling, it dies. I was thinking maybe fuel delivery (?) but how would that explain that it starts up? It just won't stay running... any ideas?

 

[Explorer]

Clogged fuel line/filter, fuel pump about shot. That'll get you started looking.

 

[Jerseydevil]

I doubt this is it from your description, but check the ignition fuse. I've had it blow and the sure sign is it runs in the start position but as soon ad you let off the key, it dies. Sounds like yours is running for a few seconds longer though.
Check for fuel reaching the carb.

 

[knack]

Will it keep idling as long as you don't step on the gas? If it does, there might be something in the main jets. Water, or some scale from the bottom of the float bowl? Try looking down the carb with the engine off and see if the accelerator pump squirts fuel when you operate the throttle.

Did you just leave the gas station? Maybe got a load of bad fuel?

Didn't fill it with E-85 by mistake, did you? Don't ask how I know what happens when you do that.

 

[film915]

Clogged fuel line/filter, fuel pump about shot. That'll get you started looking.

Yeah, that's kind of my first suspicion. Before this problem, if it sat for a long time, I had to actually pour a little bit of gas in the carb for it to start - otherwise it just cranks and cranks. I'm thinking the fuel pump might be on the way out.

Will it keep idling as long as you don't step on the gas?

No - it will only idle for a couple seconds, maybe 4-5 seconds at the most. And if I hit the gas during that time, the engine dies right away.

Did you just leave the gas station? Maybe got a load of bad fuel?

No, but I actually thought I might be out of gas at first, because my gauge is off - it reads at 3/4 when full and 1/4 when empty. So my wife picked me up and we went and got 3 gallons of gas, but the problem persists, even after sitting for a couple hours.

Anyway, I'm leaning toward a clogged fuel line or faulty pump. Thanks for the help!

 

[mudslut]

run to auto parts store and grab a fuel pressure guage they are about 10 buckets put it line , crank and see

 

[mudslut]

or easyest way pull line off carb, put in 20 oz coke bottle or drink of your choice and crank away

 

[film915]

run to auto parts store and grab a fuel pressure guage they are about 10 buckets put it line , crank and see

Cool... what should the pressure be?

 

[Explorer]

Actually, I would advise buying a vacuum tester. It doubles as a fuel pressure gauge and will really come in handy for a lot of things.

 

[Phil Munsterman]

I had a similar problem with my 76. Used a clear coke bottle to test and didn't get much fuel when cranking. Replaced filter and pump and still not much flow. It ended up that the fuel filter in the Tank was falling apart and clogging up the fuel pick up tube.

 

[mudslut]

just did this with mine with new pick up in tank and new pump mine is running at 7psi i was told 6 to 8 is best. i eneded up having a carb issue

 

[kbldawg]

any vacuum leaks?

 

[YNOTBOB2007]

I had the same issue. Turned out to be the carb.

 

[film915]

I had the same issue. Turned out to be the carb.

I'm leaning that way now. I disconnected the fuel line from the carb (filter was fine), stuck the line into a plastic bottle and cranked the engine a few times, and fuel seems to gush healthily into the bottle. So, there's no problem with spark and seems to be no problem with fuel delivery from the tank to the carb.

Did you end up replacing the carb or just rebuilding it?

 

[YNOTBOB2007]

I rebuilt it. Replaced all gaskets, cleaned all jets/orifices...just follow the directions from the kit replacing one thing at a time and set your float properly. My kit did not include the gasket at the manifold so you should buy that separate. I had crud in the bottom of the fuel bowl. After I reinstalled the carb...I couldn't get it to start. Tried and tried but wouldn't turn over. I ended up flooding it...walked away and the next morning it fired up fine. I probably should have put a little starter fluid in the bowl to start with. Been fine ever since.

 

[film915]

I rebuilt it. Replaced all gaskets, cleaned all jets/orifices...just follow the directions from the kit replacing one thing at a time and set your float properly. My kit did not include the gasket at the manifold so you should buy that separate. I had crud in the bottom of the fuel bowl. After I reinstalled the carb...I couldn't get it to start. Tried and tried but wouldn't turn over. I ended up flooding it...walked away and the next morning it fired up fine. I probably should have put a little starter fluid in the bowl to start with. Been fine ever since.

Cool... sounds like a job but one I can handle. Where did you find the kit to rebuild the carb and the manifold gasket? My carb is stock...

 

[YNOTBOB2007]

Autozone. If you have the metal tag on the carb, bring it in as they can use that to identify the carb too. Good luck! Get a brass brush too so you can clean the gasket off the manifold. No sealants when you reinstall...dry fit only.

 

[Scott C.]

Are you running the Durospark ignition? Or, are you running Points? If you are running the Duraspark you might need a new stator. The stator is the part inside the distributor. Sometimes when they go bad it will start and run until you return the ignition switch to the run position and then die.

 

[film915]

Are you running the Durospark ignition? Or, are you running Points? If you are running the Duraspark you might need a new stator. The stator is the part inside the distributor. Sometimes when they go bad it will start and run until you return the ignition switch to the run position and then die.

I highly doubt I have something other than stock. The thing's pretty much original.

 

[myclsic69]

Does it smell like it's a flooding issue? or starving for fuel? If you think your getting enough gas to the Carb. replace the points and condenssor, mine had a simular problem, a small nick from the dizzy was the issue.