BC Broncos fuel tank priming issue

[mattt]

Bronco has been sitting for a couple years after a cage build stalled the Bronco being driven regularly. I'm back at it finally and the old horse will not start. I am running Ford EFI with an external fuel pump. The pump cycles with the key on as it should. I dumped around 1.5 to 2 gallons of fresh fuel in the BC Broncos tank that was installed about 12 years ago.

I went as far as grounding the FP trigger wire in the test port so the pump would run continuously, and still can't get any fuel pressure reading at the schraeder on the fuel rail.

I seem to remember hearing second, fourth, 10th hand that some BC tanks were sent with rubber fuel hose that gives up the ghost eventually. From what I remember when I installed the tank 12 years ago, mine had rubber fuel hose for a pick up line?? I think.....

Anyone else BTDT with an issue like this? What did you do to rectify it?

I'm dreading dropping the tank since I tacked the tank in place to the brackets, as BC Broncos directions said to do. Not sure if it's better to cut the tack welds or just unbolt the brackets to get in the tank.

Could anyone offer advice on other possible ways to determine if the fuel pickup line is toast, if there are any? Yeah, I am really not wanting to drop that tank, but I suspect that is my only option.

Anything else that could be the cause here that I've neglected? Thanks Bronco intelligencia

 

[Jedeka]

Have you pulled a line off at the engine to see if you are getting fuel out of the tank?

 

[garberz]

I know when you lose the prime with an external pump, you need at least 5 gallons in the tank for it to pick up. Take the pump feed hose off and blow into it, you’ll hear it bubble if the pick-up is still in place. I think it just need more gas to prime.

Mark

 

[mattt]

Have you pulled a line off at the engine to see if you are getting fuel out of the tank?

Yes, no fuel.

I know when you lose the prime with an external pump, you need at least 5 gallons in the tank for it to pick up. Take the pump feed hose off and blow into it, you’ll hear it bubble if the pick-up is still in place. I think it just need more gas to prime.

Mark

Thanks Mark, that is a great idea, a simple way to check the fuel pick up line internally. I'll check it and see if I hear it bubble.

 

[DirtDonk]

Agree that pulling the tank is the last thing you want to do again. But it might end up being necessary at some point anyway.
However, the pump that's been used and then has sat for a couple of years is usually my first suspect. Sometimes they just die an early death from sitting.
Seems worse with modern ethanol fuels, but it's pretty much across the board at some point.

Paul

 

[mattt]

Thanks Paul. I think I'll add checking the pump to the checklist before dropping the tank. I can rig up a gas can that the pump can pull directly from.

I thought others with this tank may have already dealt with this pick up tube issue from way back when BC supplied the tank with rubber hose. I'm still uncertain if I'm going to cut the tack welds and leave the brackets in place on the frame or just drop the brackets by unbolting them from the frame.

 

[DirtDonk]

Yes there were indeed a couple of problems over the last 10 years or so, but they usually reared their ugly heads early in the tank's life I thought.
One issue was a bad weld on a steel part of the main pickup tube, that blocked part of the flow. This manifested in not being able to flow enough fuel to feed a hungry performance engine.

The other was something about some rubber tubing, like you were saying.
Don't remember if it was bought wrong, or the supplier sent the wrong grade of hose, but it was something about it falling off the pickup tube after swelling maybe? You know, now that I think of it I'm not really sure I remember the details.
But it was a fairly short-lived issue and most found out about it fairly quickly. Certainly within a year of running their rig.

In my own case I've run into faulty fuel hose issues as well. It's plumbed with the expensive EFI hose, but the end for the return line at the tank was swollen up to twice it's size and poofed up around the clamps and leaking like a sieve. Crappy stuff we get these days. And that was straight from the usual auto parts stores and rated as the good stuff.
You never know...

It's actually very easy to believe that anything made of rubber inside your tank that has been sitting is one of the suspects in your troubles. But looking outside the tank first, especially to the more likely culprit in the fuel pump, still seems like the better course of action.

Knock on wood!

Paul

 

[mattt]

Had some time to dive into this and check everything that was suggested above. First thing was pull the fuel outlet line and blow backwards to see if the dip tube is bubbling in the fuel.....with the tank cap off I could hear bubbling in the tank so I thought, dip tube isn't compromised.

Put it back together, rented the fuel PSI gauge tool and check again. Still no fuel pressure at the fuel rail....that was after 2 faulty VatoZone gauges that both leak at the shraeder adapter piece.
In the past when the pump was running I could hear the fuel dribbling back into the tank from the return line if I had the fuel cap off. No fuel dribbling back sound from what I could hear.

Next was rig up a temporary fuel pick up line to run to a 5g gas can. Did that, after about 10 seconds I heard the fuel pump sound change/drop which indicates it's priming. Good news, so I went to start it and wham!, almost instantaneous start. Woo Hoo! Purring like a kitten, err Bronco. Ran it for 2-3 minutes and restarted multiple times.

After the system was primed and running, I swapped back to the tank one more time to see if would run off the tank. Nope. It did start but was running like crap after 10 seconds and continued to get worse before dying at 1 minute. So I'm going with the dip tube is the problem here.

Yesterday I was able to suck 8 gallons out of the tank with a LP Carter pump and cut the welds from the mounting brackets to the tank uni-strut. Tank is just about ready to drop down, just have to undo the fill and vent lines. I'll report back further what I find internally. Thanks for the help guys.

 

[DirtDonk]

Well that certainly narrowed it right down! Even though you still need to drop the tank, I'm glad you isolated that way anyway. It's always better to "know" than to guess. But your guesses are pretty spot on it seems.

I wonder what exactly is going on? At 8 gallons, I wonder if the extension simply fell off and so can't suck fuel from the bottom third of the tank. That's sure what it sounds like at this point. You could hear air going into the tank, so assuming proper volume, the lines were clear.

As much as I hate the idea of cutting into my pristine floors in the Broncos, and original pickup bed in the truck, I'm planning to cut access holes for the EFI pumps in at least two of mine.
Friend did it and it came out great.

Looking forward to your next report.

Paul