Vapor Lock?


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By Duck - 15 Years Ago
Fellas; I've got a real "poser" (as my Dad used to say) and was hoping some of you might share your thoughts on the situation. We took the car out last night (cold and damp weather) and went down to our local Friday night park and hang. I'm totally impressed at the way the car runs and handles, (no problems). Arrived at the destination stuck around a while and left. went to Sunoco, bought a 1/2 tank of gas, turned into the wind, and launched for home (about a 15 minute ride). as I arrived home, I backed up the drive and waited for fair wife to go in and activate the door opener. As I waited, the car began to idle slower and slower. I backed into the garage and it just quit running all together. Failed to re-start, but the engine turned over normally. I opened the hood and looked at the sediment bowl and noticed large air bubbles being belched down through the filter element (? ) I had no way of knowing if the came from downstream or up (pump/ carb) I switched over to an aluminum intake and I'm running a 1/2" aluminum carb spacer. I'm wondering if maybe the spacer should be swapped out for a phenolic spacer? Any thought are appreciated.... /Duck
By charliemccraney - 15 Years Ago
In my experience, the only time that has happened is when the idle mixture is too rich.
By Speedbump - 15 Years Ago
One of the oldest backyard tricks around and works really well at home.  If you suspect vapor lock, pour some cool water over the fuel pump/area.  If it starts, it was vapor lock.  If it still doesn't, ya need to look somewhere else.  Another thought.....you said back UP the driveway.  If it was truly at a decent angle and you backed and your float level is on the edge of being too high, that could cause the progressively rich condition at idle that would stall the engine.  In that case, holding the pedal to the floor and spinning the engine should have made it start again.  Just thinkin...Smile
By GREENBIRD56 - 15 Years Ago
I think you ought to try a phenolic spacer instead of the aluminum. Tests I've run with the 1/2 inch phenolic show that it works pretty well as a "thermal break". If you get one, be sure it matches the carb bore size - the manifold slot is plenty big as is.

What have you done with the "heat riser" system? Is the regulator valve out of there on the passenger side? And did you try to restrict the exhaust crossover internal to the intake manifold?

By Duck - 15 Years Ago
Thanks for the help, fellas- Steve, PM incoming. /Duck
By ejstith - 15 Years Ago
Duck, I've got a whole topic on this problem somewhere on here. I have the same problem, have had it for 2 years and still have it. Mine does it like at a cruise where you are poking along with frequent stops. Just last week my latest changes was a '66 Ford 390 fuel pump (got rid of the vacuum stuff for the wipers). I had a 1 inch plastic spacer and replaced it with a half inch phenolic one. I also blocked the heat ports off to the intake manifold. I had earlier put an electric fuel pump on it, which my experience prior to now always fixed the problem. I am absolutely at my wits end. I can put a small stream of water on the fuel pump from a garden hose and it will never vapor lock & will sit & idle for hours with no problem. When you ever figure it out let me know please.