Electric Fuel pump

[Tom N]

I recently saw a question on the Frazer forum where the person asked why electric fuel pumps were not on all the time but, operated with a toggle switch.

 I also wondered about this and had another question.  Does the extra pressure from the electric pump ever damage the diaphragm on the mechanical pump?  I was concerned about the possibility of pumping gas into the crankcase if the diaphragm was damaged.

 Any thoughts or advice on these questions?

[Terry T]

yes siree

[boatingbill]

This is another good reason to have your mechanical fuel pump rebuilt with ethanol
resistant materials. This happened to a friend of mine and he didn't see the oil pressure drop
(because of the gas in the oil) until the engine started banging. Is this the time to eliminate
the mechanical fuel pump altogether?

[Terry T]

I had two fuel pumps for the Willys 161 rebuilt with proper components.
I have put 13,000 miles on one and 7,000 on the other--no problems.
I have not used Stabil in either one.

[jamestyler520]

I am getting more confused than ever on this topic. I have been advised to to in an electric pump to help cure my vapor lock problem. I was advised to make sure is
T is a push type and locate it at a point lower than the tank. I have not heard about the electric pump damaging the diaphragm in the mechanical.

What's the scoop?

[Terry T]

I suggest that you call Tech Service at Carter.
They are quite knowledgeable about these issues and our applications.
You will learn that they recommend 2 bypass spurs with check valves in the system to install an electric pump properly, if you still want the mechanical one in the system.

[Doc]

Have used  electric pumps for 18 years on cars including one that did run all the time for awhile until I installed a toggle because I did not see the need except for priming and in the case of vapor lock where I would toggle the switch on. These pump work at low pressure and you can get the type that have a built-in regulator or you can get a regulator to maintain the pressure in the normal 2-5-4 psi or so. Certainly have used the same electric pump on at least a couple cars for well over 10 years and never had any problems with mechanial pump leaking. CANNOT survive in the heat with this gas now days w/o an electric pump backup. And it saves wear and tear on the starter if you use the pump for priming. There are electric pumps that the mechanical pump will not pump through, but for my purposes I see no need in that type and if you do want to maintain the mechanical pump as well, then as some one mentioned you have to do additional plumbing. Route the fuel line well away from heat source and turn the pump on as needed.

[Doc]

It appears some probelms I have encountered were more related to water accumulating in the gas from the ethanol and I since that time a couple years ago, I have been adding marine stabil. I see now where Stabil has an additive specifically to address ethanol issues but I have no experience with it.  Many different opinions about additives but generally what I have seen is that electric pumps have become very popular for the old cars if you drive them in the heat and humidity. A Carter (P4359?) or something like that is a very quiet and reliable pump (available from NAPA) and will accept positive or negative ground whereas many of the newer solid state type or small cylindrical type (available on ebay or parts houses) will not work on postive ground, so you muct hook them up as negative ground.

[dpledger]

I replaced the original AC pump in my '53 in the early 60's with the equivalent Carter and have never had any problems in 125K miles. Just rebuilt it and seemed still OK. Never encountered vapor lock. It seems I heard something long ago about Carter pumps being less of a problem in this department, but can;t recall exactly what the deal was.

WRT ethanol, it is an awful idea. I have switched everything I own that requires gasoline to ethanol free premium. With gas prices at the present level the increase in mileage with this grade outweighs the extra cost. I currently have an Audi, and last year there were bad problems here in the north with alcohol, and the local dealer advised not using it. Can't imagine ever putting it in a Kaiser.

[jamestyler520]

Thanks for the suggestions. I didn't have problems when the weather was cooler. We have been in high 90's and low 100's for last few weeks.

It sounds like my options are
1. Electric pump with built in regulator if I keep mechanical pump
2. Electric pun that will completely bypass mechanical.

Not totally clear about option 2

I really appreciate the suggestions.

By the way I was awarded a trophy today at a local car show by one of the show sponsors rather than an official judge. I did go to show to compete but rather to enjoy the day, but it was a nice treat and credit to the car.

[j762538]

congratulations on your trophy, good to see people taking their cars to shows.

[Doc]

Option 1 provides you a back up element from a couple of perspectives:

The electric pump is there for priming and in case of vapor lock.  And if your mechanical pump did go out (leaking or whatever), with a length of 5/16" rubber fuel line and a couple of fittings you can bypass the mechanical pump completely....such is the case on one of my '51 Frazers and I have a '56 Nash running that way for now.  BTW, the occassional pumps I use mostly (solid state type) (different than the Carter), I am using no pressure regulator as I acquire the low pressure type (<4-4.5 psi.).  At least we have some choices on installation.

[Tom N]

See Also "Resolving K-F Vapor Lock" discussion.  there is also an interesting article on ethanol on the Hagerty Insurance co website.