Sputtering And Stuttering

Do another picture. That one is useless.

 

A post by SweetPea reminded of the vented/non-vented gas cap. That resembles the issue.

 

It's very hard to tell from your picture, but the stock fuel line makes a tight u-shape out of the bottom of the fuel pump. If the tube isn't crushed, that might be normal.

 

I'll try to get a better photo today. Light was terrible yesterday. It makes a U bend, but in the arc the tubing is flattened, creating what looks like a reduction in diameter. Really hard to see unless you're looking for it.

 

If you look at bottom of photo, that's the fuel line arcing from fuel pump. The apex of that bend is flattened, reducing diameter of line by half, at least.

 

But when the fuel passes into the carb, the orifice of the float valve is measured in thousandths of an inch, and the volume of flow that needs to pass is tiny. (?)

 

This. A Dauntless at cruise speed is not a 500hp full throttle big block that can easily be fed with a 3/8" fuel line. The restriction caused by that is not your root problem. It sounds more like a clogged filter, no vented cap, or failing fuel pump. It's not the time a year for vapor lock or I would also add that to the mix.

 

The cumulative knowledge here is absolutely crazy. I'll start with a new fuel filter.

Thank you all for the assist!

 

As I've learned on here, its best to systematically work your way through the problem instead of jumping around. Helps you really narrow down and eliminate possibilities. I'd start at your gas cap and work your way forward. This way, you're starting with the easiest/cheapest fixes and working toward the more complex (albeit still easy enough) fixes.

1. Start with making sure you have a vented gas cap.
2. Blow the fuel lines out and maybe drain your tank to see if there are big chunks or debris.
3. Make sure your fuel pump is free of debris as well.
4. If your fuel filter is attached via rubber hose clamped to metal line. Either add a bubble flare, an extra clamp (or 6), or think about replacing the filter with one you can "hard line" into your system. The "sucking" side of the fuel lines (everything between the tank and pump) creates a huge amount of negative pressure that could be sucking air into your lines without leaking gas.
5. if you have a metal fuel filter, make sure it's not too close to your exhaust, manifold, or right up against your engine. They can become heat syncs and cause the fuel to boil in the lines. While you're at it, do the same check on all your lines to make sure they're good and far from heat.
6. Blow through the lines between your pump and carb (with them off the vehicle) to make sure nothing is trapped.
7. Pop the top off the carb to make sure the float bowl area is free of debris and make sure the float is adjusted correctly.
8. If you have never done so, Take a stab at removing the carb all together and cleaning it out yourself. It's easier than you think and its a great way to get accustomed to your vehicle. Carbs need cleaning every couple seasons anyway so it'll save you a ton of $$ getting used to doing it yourself.

Oh and when you're done, Consider adding some seafoam to your fuel at every fuel up. It helps with breaking down any varnish build up, and helps clear out microscopic crud from your fuel system and carb. And helps keep it clean and happy longer.

 

Sorry for reviving an old thread, but I wanted to thank everyone for their input, and to say that I've solved the problem. It was vapor lock due to boiling. A little insulation on the fuel system, a modification on the location of the filter, and the problem went away.