Fuel System: Fuel delivery problem - diagnosis help needed

[showbizkid]

For the first time ever since putting Barney back on the road in 2008, he gave me a scare today. I was out running some errands when, climbing a moderate grade, I felt the symptoms of fuel starvation:

• loss of power, like way too much air in the mixture
• easing off the throttle got power back
• more throttle revved him up, then lost power again

I got up the grade in a kind of start/stop manner and once back on the level, the engine performed normally. Going downgrade, no problem - normal operation. But a couple more uphill sections gave me the same fuel-starvation symptoms. I thought maybe I was short on gas, so I filled up, but he only took 8 gallons, so there must have been at least 4 gallons in the tank.

Any suggestions where to begin diagnosing this? Tank filter? Inline filter? Plugged vent tube? (The spiders are pretty active around here.) Carb float?

For those who don't know, Barney is a '63 Standard with WCFB, 259 and Flight-O-Matic.

I appreciate your help!

[64V-K7]

If you had a smooth loss of power going up a hill, it could be the coil failing. Taking it out of gear and having the engine rev up would also fit the scenario because you're taking the load off the coil. Going downhill there is a reduced load, so that fits the situation also.

[GrumpyOne]

1. Check the fuel pump pressure

2. Pop the distributor cap and make sure all is OK there

3. Float level on carb, raise it a bit

4. Plug and wires for leakage (arcing)

5. Long shot but did some critter build a nest in the exhaust?

[doofus]

Check your fuel pump for pressure and volume. watch it fill a clear bottle, should be a strong gush of fuel with each revolution of running engine. may need to rebuild your fuel pump. Luck Doofus

[Mrs K Corbin]

I'm leaning towards float setting myself. Especially after saying you went up a hill....

[mapman]

First thing would be to replace the fuel filter. If it still has the original pump there may still be a filter in the bottom chamber of the pump. Remove the screw on the bottom to check it.
Rob

[karterfred88]

To me, if you feel like it's starving-leaning out, it probably is. Check the rubber hoses from the frame to the fuel pump and tank to fuel line. Suction on these due to higher fuel demand will cause them to collapse internally if they are coming apart. Lower the demand and enough fuel flows to make it seem alright. I'd replace them, and the filters first-replace the vented cap with a new one, blow the fuel line back towards the tank (in case its clogging at the tank outlet) and retry. Cheap, fast, easy. If that doesn't work then dig in.

[StudeRon956]

For the first time ever since putting Barney back on the road in 2008, he gave me a scare today. I was out running some errands when, climbing a moderate grade, I felt the symptoms of fuel starvation:

• loss of power, like way too much air in the mixture
• easing off the throttle got power back
• more throttle revved him up, then lost power again

I got up the grade in a kind of start/stop manner and once back on the level, the engine performed normally. Going downgrade, no problem - normal operation. But a couple more uphill sections gave me the same fuel-starvation symptoms. I thought maybe I was short on gas, so I filled up, but he only took 8 gallons, so there must have been at least 4 gallons in the tank.

Any suggestions where to begin diagnosing this? Tank filter? Inline filter? Plugged vent tube? (The spiders are pretty active around here.) Carb float?

For those who don't know, Barney is a '63 Standard with WCFB, 259 and Flight-O-Matic.

I appreciate your help!

Drive it until it reaches normal operating temp, then stop in a safe place where you can go full throttle in first gear if it does a nose dive trying to reach higher rpm its a fuel problem , ignition problems are usually jerky like turning the key off and on .

[showbizkid]

Thank you for all the help and ideas, guys. Time to dig in and do some diagnoses.

[Jeffry Cassel]

fuel pump. Same thing happened to us on the way back from a meet, but I had installed an electric back-up fuel pump. Just switched it on a cruised on home. Modern "gas" just eats rubber.

[doofus]

Fuel pump rebuild kits are available for the carter and the dreaded 4227 Airtex pumps. this might help. Luck , Doofus

[kxet]

Fuel pump rebuild kits are available for the carter and the dreaded 4227 Airtex pumps. this might help. Luck , Doofus

If you have electric tach it will usually jump around if ignition system is causing problems.

[Dan Timberlake]

Before spending a nickel, taking apart the carb or even looking up part numbers I do what doofus said in post 4.
If the free flow fuel delivery is real good, I figure the filter is still good for a while, and focus my troubleshooting on other areas.

Well, maybe the very first thing would be a strictly-for-science full throttle high speed blast on the highway as a rough test of fuel volume being delivered BY the fuel system TO the carb.

http://www.gus-stories.org/PDF/1962/October62.pdf

[Steve Winzar]

Back in 2002 or thereabouts, I filled the tank in the Triumph Stag I was using as my daily driver and proceeded to get about 12 miles up the highway before it carked it completely. I found that I had managed to pick up a really dirty batch off fuel- muck was swimming around the drawn-off sample, and completely blocked the fuel filter. After cleaning out the tank and replacing numerous filters I kept on having the same problem. It would struggle make it up hills. I tried all sorts of ideas (mainly leaning to electrical, although I did check the pump output was OK) but It just didn't quite make sense. Eventually I had the twin SU carbs removed for a professional to look at, and voila, badly clogged needle and seat on one carb. It affected the fuel level on one side as it went up hills- starving four of the 8 cylinders.
Check the little strainers in the input of your carb (if you still have them) and the needle & seat for muck.
Steve

[jclary]

Part of the reality of having one of these vintage vehicles, is the constant need for adjustment and maintenance. No matter what brand of contemporary computer controlled, permanently lubricated, covered and sealed vehicle you own...there is no "on-board" diagnostic to plug into except for the computer between your ears. For me, the simplicity of the old vehicles is part of the attraction. However, no matter how educated, how smart, or how mechanical...these simple machines can make you feel like an absolute dunce.

When they falter, you can easily make a wrong diagnosis and begin "messing" with the wrong thing/adjustment, and find yourself lost in a circle of confusion. A tiny bit of water droplet in the bottom of a carburetor bowl, getting sucked into the jets intermittently, carbon tracking on the inside of a distributor cap, a pinhole in a vacuum advance diaphragm, a dangling wire shorting out intermittently, or a loose screw...the possibilities are endless and can drive you nuts.

To me...these things are part of the reality of ownership, and although frustrating, I enjoy the challenge of working through the solutions. As recent as this week, I had my tractor in the yard attempting to pull up some surface roots from a tree-stump in my yard. As I lowered my rip plow into the ground, the old tractor engine began to spit, sputter, and finally died. It was late afternoon, and there I was with a tractor, broke down in the front yard, and ripper teeth embedded in the ground. Once I had figured out how to remove the plow, winch it onto a trailer, I asked my wife to guide the tractor as I towed it into the back yard where I could work on it. She made the statement, "not much of a tractor." I reminded her it was 64 years old, and I have not done any serious work on it in years! Not until I have thoroughly examined it, will I determine if it is "not much of a tractor."

Back to "Barney"...your description sounds like either "orientation" (uphill) or "demand" (pulling uphill) related. Fuel delivery is pretty straight forward as you work through the plumbing/component items from tank to carburetor. However, if electrical, that old "path of least resistance" thing about current flow can really drive you nuts. I've seen cracked distributor caps, carbon tracking, fouling spark plugs, cross-firing plug wires, and other electrical components change values, short, and fail at different stages of electrical demand. Mostly unseen, and difficult to trace, and cause you to call upon your most shameful vocabulary.

Next bad news, from me, is that I am going to offer no new suggestions to those already given. I'm only going to ask you to report back what fixes the problem. That way, I can enjoy the solution without having to experience the wilderness of frustration you are going through. I only hope you are able to restore the confidence you have enjoyed with "Barney" before this issue came along.