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MG MGB Technical - Back up fuel pump
|I have a 1973 MGB-GT C/B and am considering fitting a backup fuel pump. I have read Dave DuBois articles on this and wondered whether it would be practical to fit one in the engine bay and if so which type would be suitable. I realise that it is recommended to fit them close to the fuel tank but it would seem easier (for easier read 'lazy'!) to put one in the engine bay. The pump I have my eye on is the FACET Solid State Fuel Pump Road 40104 1.5-4psi. Any thoughts on this would be appreciated.|
|Paul. I located mine near the fuel tank and it has worked well. In your case, why not drop Dave a line? He has always been good about answering any questions that I have had for him. He would, most probably, be your best source for this information. If you do contact him, give him the thread and ask him to post a response here so that we can all see it and it will go into the archives.|
|For a once in 20 years occurence? Even with a points type pump? You would have to use it regularly switching back and fore from time to time to make sure it will work when it is needed, and that will wear both out together :o)|
|If you want an engine bay pump, then why not fit a mechanical pump to the engine block?|
Then you can do away with points forever!
|Chris at Octarine Services|
|Paul L. - Here is the answer I printed to nearly the same question on a different forum - An under hood mounting of a fuel pump is ok, but it can cause problems in hot weather. Because it is pulling fuel from the tank to the engine compartment, the fuel is under reduced pressure (read vacuum) when it enter the hot environment of the engine compartment and can flash to vapor if the temperature is high enough. That is the main reason that MG and other cars went to an electric pump mounted back by the tank - to prevent vapor lock. That said, as an emergency, get me home when the primary pump has gone south, it will probably work fine. |
The Facet 40104 pump would work fine as a permanently installed back up. For this kind of an installation, that will seldom be used, it is imperative to use a solid state unit as a points style pump will probably not work when needed due to the points filming over.
Yes - the need for a back up pump is probably a once in 20 year (or longer) experience, but when it does happen, it is not a pleasant one. I had the experience of having to change out a pump in 40°F temperature, with a 40 - 50 mph wind blowing and 70 - 80 mph traffic on a major interstate freeway whizzing past scant feet from me laying under the car changing out a pump while praying that one of those drivers didn't fixate on our car and slam into it with me underneath. When I got home, I decided that I was not going to have that happen again. A $40 Facet pump and a $5 switch makes it such that if the primary pump fails, I can flip a switch without having to pull to the side of the road and get home, where I can change out the pump in the comfort of my own garage. Cheers - Dave
This thread was discussed on 16/07/2009
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