It's the only thing I can figure, since I haven't had anything like this happen in 30-some years...

Filled up the wagon (carbureted 350) w/ 87 octane Valero gas Sunday nite. It has always run fine on Valero.

Monday AM gave it a new airfilter and charcoal canister filter. Drove it 20 miles into town that afternoon running newly repaired A/C, 92 degrees, close to 90% humidity. I stopped it for about 15 minutes and when I came out the car absolutely refused to start. Had to tow it home, where it finally started after cooling down about 3 hrs.

It's started hard ever since. I guess that tank of fuel is pretty hot and vaporizes right out of the carb bowl overnight. That nice clean canister filter probably ain't helping, but if you'd seen the one I picked out of it...

Yes, I know modern fuel is blended for fuel injected cars instead of our carbureted dinosaurs, but I sure hope this isn't the shape of things to come this summer.

Anyone else seeing this? My Mopar buddy said "welcome to my world". His Cuda convertible is hell to start on ethanol gas in hot weather. And natcherly closest non-ethanol pump is in NC where you pay 20 cents/gallon more tax in addition to the non-ethanol price.

 

I don't have any issues with what your describing for ethanol fuel. I'm not doubting that it may be vapor lock, but I would rule everything else out first to include bad gas.

 

Like I said, all of the daily drivers have been running fine on Valero fuels which is why I think I may have gotten a very high-volatile tank of fuel. Once the carb bowl fills it will start and run fine. I think it's evaporating out of the carb bowl overnight and also in hot soak conditions. It HAS started a bit easier today but it's barely 80 and much lower humidity.

I'm leaning toward driving the old beast to Kingsport and don't want to get stranded at a gas or rest stop, is my biggest concern about this condition.

 

Glenn,

I have had similar problems on carbureted cars when I got a tank full of high-volatility mix. Usually this happens when you get a very warm day in the winter, as the winter blend evaporates way too quickly and causes the hard start problems.

 

When the hard start condition occurs, look down into the carburetor & move the throttle to check for fuel availability. I agree that the quality of the fuel could be a factor, but I can guarantee that it won't start if it's absent. Most healthy engines will run some if given fuel, air, and a spark at the right time.

 

I had something similar happen when I first got my '83, but it was the first hot day in March we had where we were still on winter blend, as Joe mentioned above. I threw a fuel pump at it for good measure and it never happened again.

Maybe put an insulated 1/2" carb spacer under the carb, or at least make sure you have the thick 1/4" base gasket (consider doubling them). Anything to keep that carb a touch cooler in the summer time.

 

I think back in the day they used to put wooden clothes pins over the metal fuel lines as heat sinks. Now where do you find wooden clothes pins these days???

 

Wooden clothespins would be not very effective. Try something metal. Office binder clips, or, if you really want to be a badass, maybe some computer RAM heatsinks smeared with some thermal grease ziptied on.

My advice, go get a refillable old style BBQ sauce bottle with a thin nozzle. If stranded at a gas station, fill bottle, prime fuel bowl via vent tube might work, and maybe bringing a cooler of those blue ice things along or just buying a bag of ice and sitting it on the carb, line, and intake might help. Don't want to thermal shock it into cracking, though.

 

like 83 hurst i had some issues and a new fuel pump cured the problem.

 

If the wooden clothespins work it's because they're insulating the fuel line, not "heat sinking" it. Your suggested heatsinks would add heat to the fuel line, not take it away.

The engine compartment is hotter than the fuel coming from the tank. The fuel line absorbs heat from the engine by both convection and radiation. Insulating the line will be more effective than adding heat "sinks".

By the way, people might be surprised at just how hot the fuel in their tank is on a hot day. The radiant heat from the pavement puts some serious heat into the tank, even when the car is moving and all that air is blowing over the tank. Sorry, I can't remember the number right now, but I've measured the tank as being maybe 20 degrees above ambient air temperature.

But the engine compartment is hotter still.

 

Interesting points. I wonder when the fuel gets hotter than the ambient in the engine compartment. I'd put more money on the fuel line being heated via conduction from the fuel pump, bolted onto the the block, than I would over radiation from anything other than the exhaust manifolds. It'd be an interesting heat transfer study, for sure.

 

I have this problem in the 55 after pulling a long steep hill (12 miles) on a hot day then stopping to pick up my mail. The car will start but I get vapor lock about 100 yards from the post office. It's happened enough times that I expect it now.

Back in the day when I worked in a gas station and before fuel ejection it was pretty common to see carb gas lines insulated with all kinds of stuff. Rags and duct tape come to mind mostly, not something you would want on your show car.... Tedd

 

We have 10% ethanol fuel here and our summer temps get to 120, so it's more likely the base gasoline blend volatility aspect moreso than the ethanol content that is causing your issue. If it were just the ethanol none of our cars here would run from June to October.

 

I think it was just a tank of very high-volatile fuel. I burned out about half a tank and
filled it with different branded fuel and problem has pretty much gone away.


Trouble here is that all fuel comes from Greensboro NC tank farm and everything there is blended for the Piedmont Triad- which is a high-smog area. We get the benefit from that...