Jeff,
For the fuel pump to continue to pump when the engine is off, it pretty
well has to push the fuel somewhere. There are a few obvious alternatives:
1. There's a leak in the carb. This is probably due to the float valve
sticking (not cutting off), which means the fuel ought to jettison into an
overflow system which depends on the model, or depart the carb through a
faulty gasket over one or both of the float chambers. This could mean a
gas stream over a hot exhaust (ouch). Solution is to fix the float valves,
make sure the gaskets are good, and check that the overflow tube goes
somewhere safe. (I'm not 100% sure, but I think that the overflow tube on
newer models goes to the charcoal canister and from there back to the gas
tank; this would be an example of a leak that you cannot see, and is
probably not dangerous, but it would still amount to a leak in that the
float valve is not cutting off and needs fixing.)
2. There's a leak in or after the fuel pump before the carb. An example
would be a hose, union, or filter leak. Depending where it is, it could
also exit fuel on to a hot exhaust. Solution is to fix the leak.
If the fuel pump runs with the engine off, look for the leak and fix. That
ticking fuel pump is a potential ticking bomb.
Daryl
----------
> From: Jeff Boatright <jboatri@emory.edu>
> To: spridgets@autox.team.net
> Subject: Re-fuel pump run-on
> Date: Monday, September 14, 1998 4:43 AM
>
> Dear Spridgeteers,
>
> As I wrote earlier, yesterday my fuel pump ran on continuously at
start-up.
> I smelled fuel as I pulled away. It has not happened again (yet). The
reply
> I got on this is below (thanks to the sender). Has anyone else had this
> run-on problem and what were the results?
>
> >This is EXACTLY what my first Lotus did moments before it burst into
> >flames. I don't know what to tell you, other than if it happens again
look
> >for leaks, and if you find no leaks look for another fuel pump. I would
> >not screw around - I found out the hard way!
>
> Thanks,
>
> Jeff
>
> Jeffrey H. Boatright, PhD
> Editor-in-Chief, Molecular Vision
> http://www.emory.edu/molvis
> "Seeing the Future in a Very Tiny Way"
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