S4 bottom o ring (aka bottom insulator) N326-13-257

S5 bottom o ring N350-13-257

 

haha ok your talking about the bottom one, I was taliking about the 0ring that sits in groove at the top of the injector that goes into the fuel rail. The leaks occur between the fuel rail and the top grommet. The grommets are new and in perfect condition.

 

Turns out that if you want the fuel injectors to seat properly you need to make sure the fuel rails are perpendicular to the fire wall or the orings and grommets wont seal right. I would geuss because of uneven pressureon the rubber. Apparently when I would tighten them down the fuel rail would shift just enough to let fuel by. I noticed this and held it in place with one had while tightening it with the other, jumper the fuel sys and wala no leaks!