I read somewhere that there was a check valve of some sort built in our fuel lines, is this true? The check valve maintained pressure at the fuel rails while the car is shut off. My car doesn't like to start up when it's cold, so I'm starting to think that my "check valve" may be shot, because I have good fuel pressure at idle/WOT, indicating my fuel pump is still good. I checked my parts manual, and can't find any part number's for this check valve. Anybody know the technical name for it? Thanks!!!

 

There is a check ball internally in the pump. You need to monitor the pressure after the engine is shut off. Even still, a leaky injector can cause the rail pressure to drop.

 

I have a new fuel pump sitting in my garage. Maybe I'll just take the plunge and replace it. I don't think I have any leaky injectors, I would be able to smell that, right?

 

I doubt you could positively determine a leaky injector by smell. There are ways to test fuel pressure problems.

 

When I did the plugs 500 miles ago, they were all evenly colored, none were different from any other. I might just do my fuel pump anyway, been dying to try out the trapped door method!!