Driving problems! Need Help!

Hey Guys,

I have a 1997 Pathfinder that me and my dad got so that I could have my first car! And when we first got it, it was in pretty good shape, but not so much any more. It has gotten so bad that you have to literally push the 'pedal to the metal' to even get it to go! We have invested a lot of money into this car, and at this point we are just trying to get it in good enough shape to sell it so that I can have a working car for my senior year!

As I said above the car has gotten so bad that you have to push the gas pedal all the way down just to get it going! Now, I literally live right next to the school so I can get there but with it getting less than 10 MPG cause of this problem, and cause I have to leave REALLY early so I don't have to worry about slowly getting into traffic.

Anyways on to the problem! When you first start it up (in the morning or the afternoon)you have to set there and rev it up for like 5 minutes (and in this time the pedal is pushed all the way down and the RPM's are between 2 and 3 thousand) and when it finally gets to where it starts to push 5000 RPM I head on out. And, for the first 1000 feet or so the car will jerk and not go above about 5 MPH then it becomes 'normal' and gets to where it won't jerk. After this time of 'warming up' the car will do a decent acceleration to about 35 MPH then it very sluggishly accelerate upwards. And, even after a decent amount of time driving it (about 10 mins or so) it still drives up to the 35 MPH mark and so on. Also, when I'm driving it home (so in the afternoon; never done this in the morning) the RPMS will start to drop and die suddenly unless you feather the gas to stop it, and when this happens it will sit their and flood itself to death. It will also flood when you go to start it at about any time after driving it. It sometimes does this in the morning if I stop for breakfast but it will start up after about 5 - 10 seconds unlike in the afternoon when it will literally sit there for almost a minute flooding.

Now, on to what my dad and I have done. We have replaced the fuel pressure regulator, fuel pump, fuel filter, MAF (not a OEM a aftermarket one), all the spark plugs, distributor cap and rotor, throttle body position sensor, and the air filter. We also put in a new starter. (As you can see we are sick of putting money into this thing and not getting any results!)

And, the things we have done to it! We have ran high octane fuel and fuel injector cleaner through it (when we ran the fuel injector cleaner in it the 'warming' up in the morning got a little better). We have also tried running it with the pipes disconnected, and we have tried a working distributor from a 2001 Nissan Xterra. The computer has gave us two different codes over the last several months too. They are (I don't know the name of the codes) a misfire on cylinder 5, and random multiple misfire.

If you guys can help me I would greatly appreciate it! I really want to get rid of this Pathfinder (in working condition!) So that I can have a working car for senior year!

Thanks,
Justin