niiChan, which check valve did you order?

If it's this one offered for a mere 50 bucks from reddat...

Datsun 280z Fuel Pump Check Valve Nice | eBay

... then it's the wrong one. In fact what reddat is showing isn't even a fuel pump check valve, but rather a well overpriced air/fuel vapor check valve.

Thats for sure Sarah! I don't buy anything from him anyway....he price gouges people! I just ordered one from sam_the_diesel_man. 13.00 bucks with shipping.

Actually was 11 bucks with shipping

RCB, does Sam the Diesel Man's generic check valve work well? I've not yet heard any feedback on it. I was lucky to find one of the last almost OEM valves, actually a Volvo valve, so I didn't need to order from Sam.

Fastwomen: okay first let me say sorry for taking so long to get back with info. I did order the one from Sam and installed it this morning. Went back later, 45 minutes, and it was still holding pressure. After about 3 hours I rechecked and the pressure had leaked down to "0"! Not sure what is going on here. So what I'm going to attempt to do is pressurize the system and pull the fuel line from the fuel filter "out"(that is where I installed the check valve) and see if it bleeds back. If it does then it's the check valve. If not then I have a leaky injector, which are new! Either way I'm not happy!

NiiChan: I was having the same problem and was able to correct it (time will tell) by adjusting the air bypass screw in my AFM 1/2 turn clockwise which meant I was just a little too lean.

I will get back when I have results of the test I want to run next.

As I understand (from a long-time Nissan service tech), the system really only needs to hold pressure long enough for the engine to cool down. Holding pressure forever is ideal, but 3 hr is probably good enough.

Ah, that would make perfect sense! Thanks.