1966 Stalls

[poorotis]

Looking for some direction. Two years ago I did a valve job on my 1966 Mustang 200. When I put it back together it ran so much better with a ton more power, no knocking and great acceleration. Ran that summer fine and then part way last summer if I drove it for an hour or so it would start to run rough and would stall. Would not start back up until about 30 minutes later as though nothing happened and would run no problem.

I have read a a lot on vapor lock, but nothing has changed and cant see where the fuel line would be getting hot enough to cause a vapor lock.

Any thoughts.

Getting gas
New Rotor
New Cap
New Plugs
New Wires

Again if it cools off for more than 30 minutes starts right up.

 

[WORTH]

"run rough then stall", idling or running down the road?
After it dies, does it crank slow, or fast?
Does it try to start or just spin.

 

[Realmongo]

Does sound like vapor lock. Maybe within the fuel bowl or the fuel pump?
I also have seen a failing condenser cause similar problems.

 

[poorotis]

"run rough then stall", idling or running down the road?
After it dies, does it crank slow, or fast?
Does it try to start or just spin.

Yes. Suddenly rough idle as I maybe come up to stop sign or slow down make a turn. Not cruising along.

Cranks right over no problems wont fire. I pulled the air filter and appears getting gas, but wont fire up.

Let it sit for 30 minutes fires right up and takes off like nothing.

My plan is to replace the coil, condenser and replace the points again.

Should I go with Petronix coil on stock!

If it is vapor lock where do I start?

Thanks for the comments!

 

[WORTH]

drive it again, buy a simple spark tester that plugs into the spark plug wire, when it dies do 2 things. Check for spark at the plug, and see if the coil is very hot. Spark tester will tell you if it is a fuel or a spark problem before you start throwing parts at it. And a bad coil will sometimes get very hot when they fail, and will work again when cooled down.

 

[Charlie Cheap]

poorotis, Todays ethanol kills rubber and carb seals/gaskets. Make sure your carb is rebuilt with an alcohol safe kit. Also, sitting for many weeks can allow som gas to turn to varnish which partially plugs carb passages. Berrymans B12 will burn, so I put as much as possible in the carb bowl and run it through to clean passages. Sometimes that is all I need. Also, if you park for long periods like me, keep the tank full as possible. Ethanol attracts water and can ruin a gastank. I am on my third one. I put a see-thru gas filter in front of the fuel pump to keep an eye on rust trash in the gas and it works.