Vapor lock?
 

Any good tips on how to get rid of it?

It only happens after a long (over 1 hour) drive and i slow down and idle. the car is a 1968 camaro with a small block. stock fuel tank, stock fuel pump.. 750 demon carb, 1" phenolic spacer.

Any help?

Eric, make SURE your gas cap is venting. I had the same problem years ago and it was a bad cap that wasn't that old.

That makes me ask this ? as far as its "venting"...when I drive for a decent amount of time...20min or so and then stop for gas. When I take off the cap there is a POP and a Whoosh of fumes...the cap is supposedly a venting cap,but my thought is it isnt venting..

Agreed?

Thanks
Tim

Mine is doing the exact same thing!! How do i find a vented cap for a 68?!

The restoration places carry them; Ricks, Year One, Classic Industries, etc.

Ahhh ok, i hope this works... its only after long drives... really weird.

What is the best cap? Are there aftermark ones that are better? I just went to yearone.com and found what is supposedly the 69' vented cap...it is exactly what I have. My cap has VENTED stamped on it, so I just dont think buying the same cap again will make a difference.

Didnt I read a long time ago about someone drilling a small hole in their cap. Wasnt that you Scott? Or am I just nuts.

Tim

Tim, you have a good memory. That was me that drilled a 1/16th hole in the cap as a troubleshooting measure. At the time, it was extremely hit or miss. The car would die once a week or maybe once a month. It was acting like an electrical problem, but as it turned out, the cap was acting goofy, it just didn't fail, it was intemittent or vented extremely slow. The hole I put in the cap fixed the problem, but I ordered a new one for obvious reasons.

The same exact thing happens to me with my 440 68' Charger. Only happens after about 1 hour of constant driving. I have a vent hose from my gas cap that I blew out with my air compressor - thought that may have done it, but then it actually happened last night after an hour drive, totally annoying. I also have a spacer under the carb. - I've made sure all fuel lines are clear from any substancial heat sources i.e. headers, exhaust. I have also replaced the fuel tank and sending unit. I may try heat wrapping the fuel lines as I don't what else to do.

What is the symptom of vapor lock? I know causes but don't know what it feels like. Does the engine just stop abruptly for a second?