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Discussion Starter · #1 ·
I have a 65 mustang 6 cyl auto that I have owned since '66. It has always had a problem of stumbling, stalling and vaporlocking in hot weather in stop and go traffic. It seems to have gotten worse with no-lead fuel WHY?
One thing I wonder about is the fuel line. The fuel pump is on the left side, lower mid engine.
The carb is on the right side, upper mid engine.
The fuel line is routed from the fuel pump around the front of the engine at the valve cover height to the carb. There is plenty of exposure to heat and the possibility of fuel boiling.
Is this the likely source of vaporlock.
Would insulating the fuel line help?
I've thought about an insulating carb spacer but they don't seem to be available. Likewise for a heat shield carb gasket.
The car does still have the original carb and fuel pump
Has anybody else had this problem??
 

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Vapor lock is a common problem in the inliner engine. One thing Ford designed was that one of the heater tubes runs through the carb spacer, but that wasn't enough. The problem is worse in cold weather. You actually need to heat the carb a bit more than it is now, not insulate the fuel per se.
 

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I had all sorts of starting and idle problems with my 6. I ran across a rebuilt carb in a box. Bolted it on and it started and ran great. It is only a 127,000 mile car with a head rebuild in the 80,000 mile area.

As I recall the modern fuel is more likely to climb up the sides of jets. Throw in a float off level and some crud in the passages.

How many miles on the timing chain and valves? I think that is another area you need to think about for smoothing out the 6. Been a long time.

I remember reading about some carb company that rebuild the 1 bbl carb. They pull out the flat spots and gives it a bit more umph. I have not paid attention in the last few years so I do not know if they are still around or doing quality work. They would also replate the carb to look NOS.
 

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Oh I left out.

Weak fuel pump and old rubber lines.

The older fuel pumps get weak. My original one stopped pumping a few years ago. You might want to replace it just out of general principals.

I have noticed people tend to neglect the couple of rubber fuel lines. Cheap and easy to replace. A cracked fuel line can warm up your day a bit too much. I have seen my share of V8 mustangs with that burn mark in the middle of the hood. It is even funnier when there is a trail of burning fuel behind the car. It happened behind my house one day. I did not see the trail, but several people doing yard work did. BTW, it was not my car.
 

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Discussion Starter · #5 ·
This car still has the orig. fuel pump. I have a new one to install.
I would like to find a rebuilt or new carb but have been warned about so called repros.
 
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