2000 Sentra won't start

I have a 2000 Sentra w/ 1.8L. It has been running fine. We were gone for 5 days. When we came home it wouldn't start. It turns over good but won't even try to start. I can't hear the fuel pump run when I turn the key on. I have checked for voltage at the fuel pump. I have 11.6V on the black and green wire. I have tried all the other terminals and have nothing on them. Shouldn't one of them have a burst of power when the key is turned on to pressurize the system ? I may have a bad fuel pump relay, but I can't find it. Haynes says it is in the relay box under the hood but it isn't. I have check all my fuses. None of the local parts stores had the relay in stock so I have ordered one. Hopefully I can find it if I have an example to go by. Does anyone have any ideas ? Thanks!
Update. I have no fire. I pulled one of the rubber hoses off of the fuel rail and when I turn the key on gas squirts about 6 inches out of the hose. I guess my fuel pump is working and I just can't hear it. Does the fuel system have to have a certain pressure to get fire to the plugs? Any ideas ?

UPDATE No I still haven't got it running. But here are some things I have learned from a Nissan mechanic. If it won't start and you aren't getting any fire- turn on the key, if the check engine light doesn't come on it is probably a broken wire in the harness. Check for the white wire with a blue strip in the harness under the battery. They are bad to break here and this cuts power to the computer relay. The relay is behind the glove box. Check for power at the two blue and white wires going into the relay. If the check engine light does come on and you aren't getting any fire it is probably the crank position sensor. It is located on the back of the motor to the left ( drivers side ) of the starter. It's the one with the 10mm bolt that you really can't see. The fuel pump relay is located behind the left kick panel on the drivers side. Hope this helps someone else.

You have to check the fuel pressure; the pump may be working but not well enough. Fuel pressure should be ~43 psi with key-on engine-off. With engine running it should drop to 34 psi. If pumps working it could be the fuel-pressure regulator gone bad; if you take off the vacuum hose going to the FPR, there should be no liquid gas in it or coming from within the FPR; if there is, it's leaking/bad.
You say you have no fire; do you mean no spark? That's a separate prob from fuel pump/pressure. You can pull one of the plugs, ground it against the engine, and crank while looking for spark (make sure there's no gas laying around).
Hope this helps....

Check out :
http://www.nicoclub.com/FSM/Sentra/2000_Sentra/
for service manual; section EC has fuel pump info....

The camshaft sensor and crankshaft sensor are prone to failure for this engine even though Nissan has not formally acknowledges this problem. If you have access to a scanner check for codes P0335 or P1336 for crankshaft sensor problems or P0340 for camshaft sensor problems. This codes will set even if the engine does not start. They set because the ECU does not receive a signal from them.

Yes, I meant no spark. I have checked it by grounding out a plug. Would low fuel pressure cut the fire ?

No, fuel pump issues wouldn't affect the spark. You need to fix the spark prob, then see if there's a fuel prob. You should borrow a code reader and read/write down the codes. If there are any, the service manual has specific troubleshooting steps for each code. The 2000's are coil-over-plug (no distributor) so spark probs may be individual coil packs, ignition control module, camshaft or crank sensor, etc. Some parts stores (like autozone) will "sell" you a code reader, then give you all ur money back when you return it.
Hope this helps.

The only code it has is for an idle system malfunction. I don't believe this would cut the ignition, would it.

Did you ever find the problem? Idle system code probably wouldn't affect the spark, but could keep it from starting. So it was running fine, sat for 5 days, then wouldn't start? How old is the battery? 11.6 volts is a little low, maybe you should put it on a battery charger overnight and try to start it in the morning. If your battery is going out, it can give wacky symptoms.

No, I haven't got a chance to work on it any more. My daughter got married this weekend so it's been a busy time. I will charge the battery tomorrow. The battery is about 6 mo old but of course it could still be bad. When the old one went bad the car wouldn't shift into high gear, so you're right low voltage can do funny things. Thanks for your help ! I'll repost when I find something out.

I did everything I knew to do. I finally just sold it for parts. I hope the info I gave in earlier posts helps someone. Thanks for your suggestions!