Nissan Repair: Hard start - no idle, nissan 200sx, leaky injector

Question
QUESTION: I am working on my daughter's 95 Nissan 200sx se (1.6).
It died on her while driving. The shop it was taken to, wanted to replace the timing chains (10 hrs labor and parts). We brought it home, looked at the chains and nothing was broken.

I can get it started after priming the pump and a lot of cranking and it will run as long as I give it gas but will die at idle or under load.

Decided it was not the chains and fuel problem.

I was getting 40psi from pressure gauge in ON position and will hold for the longest time. Changed the filter and pressure regulator. Now, the problem is still there and I get the 40psi when the key is turned on but pressure drops to near zero in about a minute.

I am leaning towards check valve in the pump but someone said it could be IAC valve.

Can you point me in the right direction?
Thanks,
James

ANSWER: Hi Drew -

I agree with you. Seems like a fuel delivery problem. Check valve would be my next thing to check.

When the ignition is on, does the fuel pump still have power even when the pressure goes to zero?

Please get back to me -
aloha'calvin



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

QUESTION: As for power to the pump, a relay gives pump power for about 5 seconds and cuts off power till cranking when power is back on the pump.

According to the book, the holding pressure should be between 30-40 psi 5 minutes after the key is turned off. Our holding power goes down to 20 within 30 seconds and to zero  in 1-2 minutes after that.

I replaced the pump today and no change. A leaky injector is  the only other part I can think of being in the fuel line that can cause a pressure loss. I wish I had pulled the line and checked before replacing the expensive pump and regulator.  

Answer
Hi Drew -

Seems to me that if you have a leaking injector, you will have gas in your cylinders, unless it is an external leak, in which case you would be able to see it. That is a pretty hefty pressure loss, so if it is an internal injector, you would see it on the plugs (black carbon residue), or black smoke initially when you start the car.

Is that the case?

Thanks
calvin