[40forddgc]

What would cause vapor lock and how can I prevent it? Engine is a 383 Chevy, with a 750 Holey. It seems to happen on hot days. When it happens the engine is at normal operating temperature.

thanks

[68NovaSS]

Running the fuel lines close to hot areas, like headers etc. will cause vapor lock. If you can't route them differently, shielding or insulating them helps.

[40forddgc]

i have the fuel lines are insulated.

[moontanker]

Use cclothe pins on your fuel line ,works like majic.

[40forddgc]

Ya know I have heard the before. Did that actually solve a problem you had or is it just something you heard?

[T-bucket23]

Originally Posted by 40forddgc

What would cause vapor lock and how can I prevent it? Engine is a 383 Chevy, with a 750 Holey. It seems to happen on hot days. When it happens the engine is at normal operating temperature.

thanks

First off more information would help like what is the engine in.
How do you know it is vapor lock, vapor lock is not a real common issue anymore.
What are the symptoms and what do you do to fix it.

[cobalt327]

Gas formulations vary with the seasons and geographical location.

If you last fueled up and it was the middle of winter, the problem might resolve itself with a fresh refuel. Same thing if the car came from a cold climate to a warm one.

Never heard what the deal is w/the cloth pin trick, but heard that forever. Maybe it creates a mini-heat sink? (Unlikely w/a wood pin...) Dunno.

[40forddgc]

The engine is in a 1940 Ford street rod. The last time it happened is when I exited the freeway and when I took off from the stoplight the car crapped out and after a few seconds it was OK.

[cobalt327]

Makes me wonder, because usually a v-lock doesn't resolve that way, nor present that way, either. Often, it's a no-start condition after hot soak...

[40forddgc]

That's what I would think also. if you have any suggestions let me know.

[cobalt327]

See if you can recreate the problem, it might just be transient- i.e. "one of those things".

You could look to the filter (unlikely) or possibly water in the fuel or dirt momentarily plugging an orifice in the carb.

[40forddgc]

I am going to check the filter. thanks

[cobalt327]

A new filter can't hurt.

If the car's been sitting unused for awhile, like if this is the first time in awhile that you've had it out, don't discount water being the culprit. Or if the fuel level is lower than normal.

The water can get stirred up when cornering and such (you mentioned exiting the freeway). Enough so, that it can be drawn into the fuel line/carb/engine.

Dry gas may help, but a better solution might be to drain the old gas and replace w/fresh.

Good luck.

[Jmark]

I had the same problem on my truck. Either a long hard run or extended idling. Then take off, get into it some and it would crap out. Usually would finally take off but sometimes died completely.
After a long time of nursing it along and trying different things, I cked the pump pressure when hot and had 1 whole pound! LOL Changed the pump and not a problem since. Worth a check.

Mark

[40forddgc]

Certainly something that could be possible. Could the pump lose pressure when it get hot. When it craps out its always when the road conditions are hot.