Smell of gas when decelerating

[auret]

When I'm driving at cruising speed in my 1970 280sl and decelerate even moderately you suddenly smell  fresh gas in the car. There is no smell noticable driving around town or when the car is stationary. No visible leaks and no noticable smell of gas in the trunc. Any ideas?

[Peter van Es]

Did you overfill the gastank? Is the cork gasket at the fuel sender unit completely dry? There's an overflow there that would get filled with sharp braking if your tank is really full, I think...

Peter

[Cees Klumper]

This is a puzzler - principally because the 'no visible leaks' and 'smell fresh gas in the car' seem irreconcilable. Since you have a late model Pagoda, you probably have the fuel shut-off solenoid on the fuel injection pump. Maybe there is a leak there (on the fuel injection pump)? I would really look around for leaks in the engine bay and perhaps under the car; it seems very unlikely you can clearly smell gas in the car without there being some kind of leak. Good luck tracking this down.

[66andBlue]

Do you need to be driving or can you just increase idle rpm to 3500 and then take the foot of the pedal while standing? Can you smell gas?

[Jonny B]

A friend had a problem with a fuel leak due to corrosion at the top-front of the fuel tank. Not a problem in regular driving, but he would get the gas smell, and all the hoses and such were properly in place.

[Shvegel]

Verify your ignition timing. I chased the same problem until I discovered my timing was too retarded leading to unburnt fuel out the tailpipe.

[auret]

Thanks for all the suggestions - I'll follow up on them and get back to you.

I know the ignition timing is correct as I set it to specs 3 weeks ago. Probably running a bit rich though.