when did the check valve arrive?
 

Conventional wisdom is that going after the check valve is a good first attempt at ending a hot start problem. In what year did the check valve appear? I can't find one in my '77. Where the 80-83 SCs have the check valve threaded into the fuel pump, my fuel pump has a threaded pipe with no check valve. Either my check valve is somewhere else, or the '77 doesn't have one. Which is it?

Doug

Before '80 the check valve was doen inside the pump. Not visible, not serviceable.

The late external check vave can be retro fitted

Bill,

thanks for the info. In retro fitting the later check valve to my car, does that simply involve getting the 12 MM banjo and cap nut and attaching that to the fuel line? Those banjos seem pressed onto the end of the line... if I need to do that, where do I go to get it done?

Doug

The external plumbing is quite different, the older pumps(silver) have a female connection to the chassis lines.

The new pumps(black, # 911.608.102.02) have a male connection,

I bought a new pump which comes w/ the external check valve. I have heard that the external parts can be interchanged but did not do that. This was all done 12 yrs ago so but I don't recall any major issues. The new pumps are much improved internally as well. The older pumps are nearing the end of their service life after ~50k mi.

I believe that this may be the source of an issue some of the 3.6 t/p guys have i.e. lots of cranking to start.