Fuel drain back out of filter?

[gprice]

On my 1979 carb spider the PO had an electric fuel pump instaled in back at the gas tank and it still had the mechanical pump on it also. I had a problem with the engine cutting out and I change the fuel filter at the carb and this did not solve the problem. I completely removed the electric pump, checked the filter in the tank ( looked to be clean ) and gas was clean. The car restarted fine and I drove it for about 40 miles on back roads and main highways in order to run at various speeds.
It seemed to run fine but now the fuel drains out of the filter at the carb overnight. Is this normal? Thanks for the help and advise.
George

[majicwrench]

They should have never made clear fuel filters.
Is the fuel draining back causing a problem?? Why worry about it???
Is it normal??? Well, the mechanical pump will have a flapper valve that is supposed to keep the fuel from draining back. BUT ...just because the fuel "drains back" doesn't mean there is anything wrong. Heck, the fuel volume will contract as it cools too, maybe that is causing it.
Don't worry about it.
Keith

[gchocevar]

Keith,

I had the same problem with my 79 that I am rebuilding. I had to pump the accelerator and crank the engine to get the gas flowing. I found two problems with mine. The Fiat Shop manual shows a check-valve in line with the fuel filter. Mine did not have this so fuel drained back to the tank The only one I could find that was cost effective was at Summit Racing. It was a Carter check-valve. I think I paid $25 but also had to buy fittings. There is also a small plastic check-valve in the return-line from the carb. Mine was all gummed up. I removed it and dowsed it with carb cleaner until the check valve rattled when you shook it. No problems on start up anymore.

Good luck
Greg

[majicwrench]

As per my previous post, if it is causing a problem then by all means fix it, but there is no reason to worrry about the filter draining if everything else works.
The mechanical pumps have the "check valve" in them. I took mine apart and cleaned it.