Vapor lock, fuel separating issues

SRountree

SRountree

Well-known member
Joined
Apr 12, 2015
Messages
355
Location
Cincinnati - Middletown OH
My car starts up great, idle, runs awesome, but after it warms up, it won't stay running. I checked the temperature at the base of my dual eldebrock carburetors, average 130 degrees. From what I researched, the fuel is separating or Vapor locked

Things I changed to help,
1- added a 1" spacer under both carbs to help the airflow
2- added an electric fuel pump
3- added a fuel regulator with a return hose to keep the fuel flowing,
4- reran the fuel lines to keep away from the headers.

I started it up and it was flooding out.
I purchased a 3 wire oil pressure switch to turn on the fuel only when the oil pressure is on.

Im trying to figure out the wiring right now.

Any help or suggestions would really make my day! My wiring idea is attached. Im not sure it's right or not.

Thanks in advance.
 

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Not sure about the 3 wire oil pressure, or the 87a wire (looks like it's not used), so that is good. Either should work.
 
rtj said:
Double check fuel pressure, maybe? If fuel pressure is okay, neither of my cars flood.
Click to expand...
I don't get a reading on the gauge but the fuel is strong going to the regulator and the return line. Im assuming, the carbs take what they need and the rest of the fuel goes back to the tank. So not to worry about the pressure?
 
I’d suggest getting a cheap fuel pressure gage and verify the pressure at the carb. If you got an efi setting on the regulator it might be the issue. I know my magnaflow regulator has a screw adjuster it came set for efi. I forgot what the other has.

It know I chased vapor lock issues for a while.

My underhood was hot enough to fry the diaphragm in my original pressure regulator. I finally sent the nearly new carb back for rebuilding. They said it was full of red junk ( I assumed the diaphragm).

Could sealing on the spacer be an issue?

Did raising the carbs an inch impede the flow (like the old style pull choke). Can you run with the hood propped open a couple of inches like some of the racers?

Junk in the fuel bowl might mess up the needle seating. Just a thought.
 
Last edited:
This might not apply to you, and I’ve posted this before, but the most effective thing for vapor lock (and cheapest) was a small pusher fan in front of the rad. When I get back on this, probably go aluminum rad with dual electric fans.


Granted the pusher was probably the last change, so there were other factors.
 
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