Nissan Repair: Starting problem, mass air flow sensor, fuel pressure regulator

Question
QUESTION: Hello Calvin, I have a 1994 Maxima that at start-up  in the morning sometimes will crank but no fire-up. if first starting failed, the engine can not be fired up at all after that. This only happens at first starting. Once the engine is warm, it will start normally. I found it depends on environment because only in rainy and humid days, it happens. In other days it starts up normally and engine works perfect.
I changed the fuel filter. There is a high pressure of gas between fuel filter and injectors. It means that the injectors are not opened up. I cleaned the mass air flow sensor, but I still have this problem. I guess it could be something related to a sensor.

ANSWER: Hi Soren -

Can you do this test for me? -

When the engine is not starting, pull off a spark plug wire and insert a screwdriver into the boot uuntil it wedges against the metal terminal inside securely. Hold the screwdriver shaft about 1/4" away from any metal surface of the engine and have a helper try to start the car (do not touch any metal surface while doing this). See if there is a spark jumping between the surfaces.

I am trying to determine whether your problem is fuel related or electric related.

Please get back to me -
aloha
calvin

---------- FOLLOW-UP ----------

QUESTION: Hi Calvin,
Thanks for your prompt answer. I did the test. There is a spark.
Furthermore, there is not any error code (code is 55, means no malfunction). By the way, if I open the housing from out of fuel filter and empty the gas between fuel filter and injector, the car would start!

Answer
Hi Soren -

OK, now we know the problem is fuel related. It is interesting that the car would start when you release pressure. In any case, I would check items like the fuel pressure regulator, perhaps there is too much pressure.

Have you had the fuel pressure checked, before and after the regulator?

thanks
calvin