Pickup Just Won't Start!

Hello All,
First time here, and boy, do I have a whooper. Well Maybe not. My 91 pick-up seems to be dead. It has a 2.4 liter motor, and a 5 speed, 2 wheel drive. The other day as I was trying to get on the highway, the engine just stopped. I tried to restart it, it would turn over, but would not fire. Almost like it was out of gas, but it was not. I changed the rotor and distributer cap, and have good spark from the coil. I checked the timing chain, and it is intact. (that happened once before). I have ordered a new fuel pump. The fuel pump relay and fuse are good. Any thoughts?
Domo Arrigato

It's probably the fuel pump but have you tried the gas filter?

Thanks Will,
The fuel filter is practically new, maybe 1000 miles, but I will stick a new one in just to be sure it's not all buggered up. I did some more trouble shooting sort of red-neck style, but here's what I found. I checked the voltage that energizes the fuel pump relay and it was good. I ohmed out the relay contacts with the relay energized, and they were good. I hooked up all the electrical connectors and checked for 12 volts to energize the pump. That was also good. Here's where the neck part comes in. I got a bucket of gas, and put the pump in it plugged it in, hit the ignition, and it shot gas quit a way. I must assume, (bad move I know), that the pump is good. I rigged up a bicycle pump with some rubber tubing and blew out the fuel lines from the input to the fuel filter to the tank. (the lines were not connected to the tank) No gunk or debris came out, just more fuel to clean up. I decided to check all the connections to the injectors, throttle body, etc. When I removed the air breather base, I found a plug with 2 wires attached to it. One was broken. The wires were attached to some kind of sensor in the base of the air breather. If this were a piece of electronic gear, I would say it looked like a small capacitor, or perhaps a diode. It is orange on each end, and clear in the middle and has two leads, one from each end. I have pratically torn apart my Haynes, and Chilton trying to find out what this little doodad is, but no luck. Could this be my problem? I sure don't know what it is. Any clues anyone?

What your talking about in the air cleaner is an oxygen sensor. I really doubt it's your problem but I'd hook it back up or replace it just to leave nothing to chance. Your problem has me fooled. I would have guessed the relay,wiring or the fuel pump. If you can't get some answers here, try the Nissan forums. There are some really knowledgeable people there. Not that there aren't here, but some those guys/gals are fanatical Nissan gear heads.

Try a compression test on your motor.

Thanks for the input Maximagirl,
Unfortunately, according to the Haynes and Chiltons manuals, I need to get the motor up to operating temps to do a compression check. I would just like to get this thing to operate at any temp. I found out what the little sensor was/is. It is a air teperature sensor. According to the books, it is one of about a zillion sensors used to determine the amount of fuel fed to the injectors. The problem with it was one of the wire leads had pulled out of the housing. I am an electronics tech, but even with 20 years experiance soldering stuff and fixing wires, I could not fix this one. I got a new one from the Nissan dealership. ($56.00) Unfortunately, I have done so much and tried starting this thing so often, my battery is now on it's last legs. A friend is bringing me a battery charger tommorrow. The Nissan folks were very sceptical that this would fix my problem. My thought right now is this was the only visable defect, so I have to go for it. The broken wire would cause the sensor to drop all of the applied voltage from the ECCS all the time. I have to wonder if that wouldn't screw up fuel scheduling. Don't know, will find out after charging the battery.

Refer to subject line. I got the truck running, don't know if it was the installation of a new fuel filter, or the sensor. I was too excited that it would start I forgot to disconnect the sensor to see if that would indeed cause a no start indication. While she's running, I still have major issues. Idle only about 250rpm, and incredibly rough. With the pedal all the way to the floor, only about 1000 to 1200rpm, and if I put it in gear and engaged the clutch it would stall. It almost ran as though one of the spark plugs was not firing. I installed new plugs and plug wires. Changed the oil and filter, and put in a new air filter. All to no avail. I did the self diagnostic mode III thing, and the only indication I got was a 55, all ECS cicuits operating normally. Heads, compression check now as Maximagirl suggests, fuel pump....OK, what have you got for me.

The timing might be messed

Was this fuel injected?

Also, what about a vacuum test?

Your timing chain might have slipped a tooth?!