Fuel Problem

[Desert Rider]

I live in Albuquerque, NM at about 5000 elevation. Went wheeling last weekend with some local guys. Drove out to Mt. Taylor (about 80 miles) with no problem, then drove another 25 miles on dirt roads to the top of the mountain. On the way up the mountain (at about 9500 elevation and 80degrees outside temp), my bronco started to sputter out particularly on up-hill grades and then finally quit. This occurred using either gas tank. I got it started again, and then came back down the mountain. Then, on my way going home on the interstate (at about 90-95 degrees outside temp), the bronco also sputtered out on any kind of an uphill grade. Any suggestions for a problem and fix?

 

[DuctTape]

We will need to know more about your fuel system. EFI or carb? Type of ignition system? How old are components in fuel and ignition system? That sort of stuff.

 

[70_Steve]

From your Gallery it looks like you're still carbed, not that that makes a whole lot of difference.

Sounds like your fuel supply is being restricted. When you need a bunch of fuel you can't get it. Obvious place to start is fuel filters.

 

[Desert Rider]

Concerning my fuel problem, my bronco has 49K original miles. To my knowledge, every is stock and maybe be the original part. Thanks for you input...

 

[70_Steve]

... my bronco has 49K original miles. To my knowledge, every is stock and maybe be the original part. ...

Well, I think you should sell that Bronco to me, and get one that runs!!!:-X;D

 

[75junebug]

My factory pump had problems pulling fuel from my 23 gal tank thru the plastic lines and fuel selector valve. Also had a bit of vapor lock. I replaced the mechanical pump with a low pressure pump mounted near the tank, and steel tube/braided nylon 3/8 hose. My aux tank is not hooked up.....

 

[PaveBronco]

I had my Bronco out there for 15 years,,,you got the classic NM vapor lock..
I moved the fuel line away from any hot parts (engine, exhaust) and cover with that foam pipe insulation, wooden carb spacer…helped with the fuel boiling in the bowl. I also put an electric pump in, out by the tank to push the fuel to the engine driven pump..also works as a back-up.. the fuel line routing was the best fix, get rid of any metal fuel lines they conduct heat…
Next time try the Zuni's...they're on the other side of the freeway.....

 

[mini73]

My factory pump had problems pulling fuel from my 23 gal tank thru the plastic lines and fuel selector valve. Also had a bit of vapor lock. I replaced the mechanical pump with a low pressure pump mounted near the tank, and steel tube/braided nylon 3/8 hose. My aux tank is not hooked up.....

Not to hijack but what low pressure pump did you get and where? I'm kind if having the same issues. I'm still using the mechanical pump and was thinking if replacing it with an electric one. I don't know which one to get cause I've seen where the edlebrock carbs don't like to much pressure

 

[75junebug]

I run a Carter vane style pump. Dont remember the Pt number. I hated the design when I had my Ram diesel, (as a lift pump), but it seems to be working well with the Bronco. Just make sure you have a filter between the tank and pump.

 

[jckkys]

I've had similar problems here in Az. Every time this happened the answer was a repair or simple maintenance procedure that fixed things. There are some modifications that help Broncos but your problem doesn't call for a different fuel system. A properly working original system won't die on grades or in high temps. Trouble shooting guides in books or on line are easy to find. The obvious places to check are the filter, as 70steve pointed out, or the pump. If these check out look at the fuel lines. The trouble shooting guides are a logical way to find the real problem. Replacing components without doing this, is a waste of money. If Broncos had design deficiencies that caused the problems you're having, Ford would have changed the fuel system in '66.

 

[75junebug]

Exactly. My plastic lines were old and brittle, and sometimes kinked, and possibly leaked air on the suction side. The mechanical fuel pumps available today are prone to leaking fuel into the crankcase. In my case, it was easier, and cheaper to go ahead and replace with upgrades that have known value rather than falling flat again with new factory parts on the side of the mountain. Why waste time trouble shooting known issues and replacing with marginal parts.......

 

[jckkys]

Sounds like someone buys Chinese parts at Auto Zone.

 

[jim3326]

Not knowing exactly what and where your filters may be placed, I still think there is crud on your pickup screens. Since they are original, it stands to reason they would both clog at the same time. 40 years of evaporating fuel can do some funky stuff.

Jim W.

 

[Desert Rider]

Working on Problem

This week I took an initial step towards remedying my problem with experiencing sputtering or lack of fuel on uphill grades. I replaced the fuel filter located between the fuel tank selector valve and the fuel pump. I also replaced the fuel pump, which by the way, both bolts holding the pump were very loose. I also wrapped the entire fuel line, from the fuel pump to the carb, with heat shield/tape.

I am also considering replacing the filters on the fuel tank sending units.

We will see if this fixes the problem.

 

[Unaweep]

I just put a Carter fuel pump from NAPA on mine..no issues. Running a Q Jet carb.

 

[jckkys]

Fuel filters go between the pump and the carb if you had a filter that the pump was pulling through, it was not original, and most likely it's the cause of your problem. Apparently your Bronco wasn't as original as you thought. Most likely there's more Rube Goldberg modifications some knuckle head did. As I said Broncos as built didn't have your problem. So few people on this sight have any idea what Early Broncos were as new, it's hard to know what was done by POs. When folks get one of these trucks, they tend to think what they find was inferior parts original and replace them with more after market crap. Buy a shop manual and repair things by installing correct parts. You'll be surprised how nice these trucks are.

 

[Desert Rider]

Remove unnecessary fuel filter

Thanks Jckkys, and I will remove the unnecessary fuel filter.

 

[moses_m]

I dont believe the filter is your issue. I read that your pump bolts were loose. If your ground was connected to one of them that could make your pump not work. Several people including myself run a filter before electric pump. I run the Carter 4070 and I also installed a single fuel line kit with filter and 15 psi gauge. With guage you can constantly monitor pressure to carb.

 

[WheelHorse]

Desert Rider

Did you back blow the old filter (use your mouth) onto a paper plate to see if she was full of fine silt?

If she is original, don't forget to check the filter screwed into the front of the carb.

 

[.94 OR]

Any update?

I'm dealing with something similar.