Vapor Lock..

[67coronetman]

Ok guys i have read about the cause of Vapor lock and i am 100% sure that is what is happening to me which all my mopar buddies with bigger motors & cams and so on are not having that same issue. This really sucks, i have the main fuel line routed away from heat as much as possible plus i have a heat shield on my motor. i have had a good friend tell me to check a few things which i am going to do. i have also read where others have ran a fuel return line and it helped, so what say all of you any ideas would be very helpful..

Thanks so much.

 

[lewtot184]

return line or use a factory style vapor separator in conjunction with a return line.

 

[Frank Mopar]

Exactly what is the problem you are having?

Sometimes ignition problems can seem like fuel issue. I had a problem I would have bet a million it was fuel. car was hard to start when it was hot. Turned out it was the reluctor gap in the new dizzy was way off.

Where are your buddies running the fuel lines that you aren't?

Good luck Keep us posted

Regards
Frank

 

[SUPERSTOCKRACER]

I run a fuel return back to the cell, keeps your fuel cool

 

[383man]

Make sure its Vapor lock and not fuel boiling in the carb bowls. If you run pump gas the fuel can actually start to boil in the carb bowls if it gets to hot. But this causes the eng to boil fuel out the carb vents and go right down into the eng which causes the eng to load up and run rich and flood out. Vapor lock is fuel boiling in the fuel line and it actually cuts the fuel off so the eng starves for fuel. I see alot of street cars that run pump gas have the fuel boiling problem. Even if the car runs a normal 185 to 200 degrees the fuel can still get hotter under the hood. My buddies car was boiling the fuel and flooding his eng out on a 95 degree day when his eng itself was only running at 185. This cheap pump gas can boil about 190 or so and with the eng heat rising off the eng and the header heat the fuel can get hotter then the eng is running under the hood.
Can you tell us just how your car acts ? Ron

 

[cdr]

I run a fuel return & a non metal carb spacer, air temp gets over 100 deg down here in Southeast Texas, my car is 68 Charger 512ci, COLD AC & has no vapor or boiling fuel problems

 

[Dodge 330]

Phenonlic 1/2" carb spacer helped mine a LOT!

 

[actionange1]

What fuel pump?
Line size and fuel pressure?

 

[67coronetman]

My fuel pump holds consistent 6 Plus pounds of pressure it's a hundred 30 gallons per hour pump and my line is half inch

 

[67coronetman]

Phenonlic 1/2" carb spacer helped mine a LOT!

Yes i have that type spacer

 

[67coronetman]

I run a fuel return & a non metal carb spacer, air temp gets over 100 deg down here in Southeast Texas, my car is 68 Charger 512ci, COLD AC & has no vapor or boiling fuel problems

No return line yet but i do run a non metal set pacer to

 

[67coronetman]

Make sure its Vapor lock and not fuel boiling in the carb bowls. If you run pump gas the fuel can actually start to boil in the carb bowls if it gets to hot. But this causes the eng to boil fuel out the carb vents and go right down into the eng which causes the eng to load up and run rich and flood out. Vapor lock is fuel boiling in the fuel line and it actually cuts the fuel off so the eng starves for fuel. I see alot of street cars that run pump gas have the fuel boiling problem. Even if the car runs a normal 185 to 200 degrees the fuel can still get hotter under the hood. My buddies car was boiling the fuel and flooding his eng out on a 95 degree day when his eng itself was only running at 185. This cheap pump gas can boil about 190 or so and with the eng heat rising off the eng and the header heat the fuel can get hotter then the eng is running under the hood.
Can you tell us just how your car acts ? Ron

Well when I start my car up and bring it to operating temperature I can drive the car for as long as I want but once I shut it off I don't warm day it doesn't happen on cool fall days it's on warm days and I go to start it back up it will start but I put it in gear and start to pull off all the sudden it will start to sputter like its starving for gas so I have to put it in neutral or Park hold my foot to the floor and turn the ignition until it fires back up again usually it takes one to two times before it will stay running again but once it's running it's fine now I'm cooler weather and never had this issue and I do not run anything but 100% gas and at least 93 octane

 

[383man]

And hold my foot to the floor ?? That sounds like heat soak because when its flooded you need to put the pedal to the floor to give the eng more air to help clear out the flooded eng and if it never happens when driving it I would say that sure sounds like heat soak where the eng heat rises after you shut it off hot and causes the fuel to get hot and give off fuel fumes that go right into the eng and can make it very hard to start and if you hit the gas even harder to start because its already flooded. Does it blow any black smoke when you get it started and hold the pedal on the floor ? Ron

 

[67coronetman]

And hold my foot to the floor ?? That sounds like heat soak because when its flooded you need to put the pedal to the floor to give the eng more air to help clear out the flooded eng and if it never happens when driving it I would say that sure sounds like heat soak where the eng heat rises after you shut it off hot and causes the fuel to get hot and give off fuel fumes that go right into the eng and can make it very hard to start and if you hit the gas even harder to start because its already flooded. Does it blow any black smoke when you get it started and hold the pedal on the floor ? Ron

No sir no black smoke comes out at all

 

[67coronetman]

And hold my foot to the floor ?? That sounds like heat soak because when its flooded you need to put the pedal to the floor to give the eng more air to help clear out the flooded eng and if it never happens when driving it I would say that sure sounds like heat soak where the eng heat rises after you shut it off hot and causes the fuel to get hot and give off fuel fumes that go right into the eng and can make it very hard to start and if you hit the gas even harder to start because its already flooded. Does it blow any black smoke when you get it started and hold the pedal on the floor ? Ron

What would be your suggestion to taking care of this problem

 

[Frank Mopar]

Sounds like the problem I had with reluctor gap issue. Only happened when hot. Not saying that's it but it take two minutes to rule it out.

 

[67coronetman]

How do i check it please.

 

[Frank Mopar]

I'm presuming you have electronic distributor. Take the distributor cap off and measure the gap between the shaft and the pick up. Gap should be .007. BRASS FEELER GAUGE ONLY!!

 

[67coronetman]

I'm presuming you have electronic distributor. Take the distributor cap off and measure the gap between the shaft and the pick up. Gap should be .007. BRASS FEELER GAUGE ONLY!!

Yes i have a MSD DISTRIBUTOR And box

 

[SUPERSTOCKRACER]

Well when I start my car up and bring it to operating temperature I can drive the car for as long as I want but once I shut it off I don't warm day it doesn't happen on cool fall days it's on warm days and I go to start it back up it will start but I put it in gear and start to pull off all the sudden it will start to sputter like its starving for gas so I have to put it in neutral or Park hold my foot to the floor and turn the ignition until it fires back up again usually it takes one to two times before it will stay running again but once it's running it's fine now I'm cooler weather and never had this issue and I do not run anything but 100% gas and at least 93 octane

This sounds like a carb issue and not vapor lock.