VAPOR LOCK Solution

[66Sprinter]

Hey all,

Been awhile since I have been on. Been out of US for a while and busy. I have what I think is vapor lock. My built 200 is still running the Autolite 1bbl and Jon will not sell me a vaporizer model. I have yet to put on the Weber 2bbl. In the meantime, I think I am just using too much gas or its just vaporizing at the bowl or just before. I am running the stock fuel pump and saw in the tech forum a tip about using the SBC fuel pump to increase G/hr and fuel psi (from 4 to 9psi) Has anyone done this yet and why did you do it..?

Jim (Jammer)

 

[First Fox]

Why do you think it is vapor lock? What are the symptoms?

I too am considering the SBC fuel pump as I have one lying around but haven't done it yet. Looks pretty straight forward. Don't forget a regulator if you run the Weber, even with a stock 200 pump. They do not tolerate more than 3.5 psi let alone 9.

 

[MPGmustang]

the mech pump is usually good unless in drag strip conditions... where others have had the fuel PSI fall flat with WOT down the strip... the electric pump fixed this for them.

go for the electric pump, with regulator @ 5psi for the autolite, the autolite is in stock configuration too lean, that's where heat is built up from, a fatter jet and it will run and drive much smoother, my old pony carb when it came from pony carbs was 14.1 ratio on a stock engine, I went from a 59 jet to a 68 jet to get that desired 12.6 ratio at WOT, and it made a big difference in everything, including city mpg, but ironiclly it helped freeway by 3 extra mpg.

next would be timing, if vapor lock it could be too retarded or too advanced, make sure your canister is working properly, blow into the canister don't suck in the fumes with the 1100 you should have SCV, my LOM distributor went through 3-4 vacuum cans over the 2.5 years I ran it. mine in summer of 110+ heat like about 8* static timing, sometimes if light on pedal I could get 10* and an extra mpg or two...