Cadillac Repair: 1977 Caddy wont start hot, ethanol gas, fuel hoses

Question
I have been in and out of the mechanic's shop several times.  Most recently I've gotten a new battery, complete tune up, a choke pull off and they removed and replaced the dashpot.  The car will restart when I make a quick trip (like into the store to pay for the gas) and when it sits for a while (like a trip to buy groceries.)  It happened off and on during the winters of 2006 and 2007.  Now it is happening during the warmer months...hence the services listed above.  It is still happening.

I have tried do research this on my own and have come up with 2 theories - both are ethanol gas related.  First was the gas can damage some of the rubber/plastic fuel hoses and pump components.  The second is that the gas is actually evaporating in the fuel line and causing a "vapor lock" until the engine cools.

Am I on the right track?  Can you recommend a brand of gasoline or some type of additive for this "antique"?  I'd much rather switch gas brands than keep paying $386.00 repair bills!

Thanks!

Answer
Am I on the right track?   NO !!.

When this fault happens are you POSITIVE that you are getting spark to the spark plugs ?.

When you know this fault is going to happen, Remove the air cleaner and look down inside the carb and manually open the accelerator QUICKY and see if you get 2 streams of fuel into the carb. Do this 3 times and each time you should see the 2 streams of fuel.


If you do not get the fuel sprays at least 3 times you most likely have a common problem with a leaking carb bowl which is dripping fuel into the engine and is partially emptying the fuel bowl OR if your spark to the plugs is weak either a faulty ignition coil and or pickup coil which are HEAT SENSITIVE.