Fuel Issue

[rdgodwin1954@gmail.com]

Cannot find my past entries on vapor lock for our '54 Special. A fuel issue, primarily thought to be vapor lock, has plagued this beautiful car's performance and reliability over the four years we've owned it. Fuel line rerouting and replacement, manifold to carburetor heat shield installation, fuel pump mechanical and electrical replacement with individual and combination setups, and carburetor rebuild were done in efforts to correct the problem. The cause was finally found to be inadequate electrical power to the fuel pump when under heavy demand such as a long or steep hill. Wiring to the pump was replaced and no further problem has occurred.

[kaiserfrazerlibrary]

The big problem in any older car (Pre-1968 model year) is that the 10% ethanol mix (E-10 gasoline) has lowered the boiling point of gas significantly.  In the case of K-F and several other makes, fuel pressure going through the pump is only around 4 psi and as evaporation and bubbles in the fuel line begin, performance drops and so does pressure from that point.  A good electric pump will raise starting pressure 2-4 psi which can be enough in most climates to make a difference; I found this out when a well-hidden electric pump was installed in the 1951 Kaiser Special Business Coupe I owned for many years. 

[konrad]

Another possibility (particularly if the fuel line has been rerouted) would be to buy only non-ethanol fuel.  Many stations sell it...find one near you at the puregas.com website.

Yes it's significantly more expensive than ethanol imbued fuel (a dollar a gallon or more) but if it stops you from sitting on the side of the road, waiting for your engine to cool sufficiently, it may be worth it to you.

[retroguy]

What make of electric fuel pump did you install?  Where did you get it?

[kaiserfrazerlibrary]

6 volt fuel pumps that will work on a positive ground set up (which includes Chrysler Corporation cars with 6 volt systems is a big help.  However, there is an additional item nobody bothered to list that has worked for me in the last two K-F products I've owned (1952 later series Kaiser deLuxe 4-door sedan and 1952 Henry J Corsair deLuxe).

In 1951 Kaiser-Frazer put out a service bulletin about instances of hard starting/vapor lock in the 226 with cars running the Auto-Lite A-7 spark plug which the company switched to during the 1951 model year.  It made the car a bit more fuel efficient, but the hotter spark of the A-7 (or Champion J8C and equivalents) made the engine operate a bit hotter and that meant more prone to vapor lock.  The company's solution was to replace the A-7 with A-5 (or equivalent) plugs and re-time the engine to the A-5 requirements.  This did it for me in the cars I mentioned.  Before that, I also had to add an electric fuel pump to the 1951 Kaiser Special Business Coupe I had in the 1980's and 1990's.

[rdgodwin1954@gmail.com]

Purpose of my original comment on this thread concerned that after trying many combinations of cures for what I thought was vapor lock, the cure was electrical and concerned an inadequate wire powering the electric fuel pump. That wire failed to deliver adequate power to the electric fuel pump when needed which was going up a long hill.