Hello everybody, this is my first post, so please bear with me.

I just recently bought a 2000 Nissan Maxima GLE with the expectations of a blown head gasket, turns out it was only the water pump. The pump was horrible, no seals or bearings left in it, so it got replaced and everything cleaned.

I have been driving the car, put roughly 535 miles on it since I've had it and now am experiencing some problems with it.

The first issue I ran into was with the transmission, it randomly slips into neutral when driving or going up a an incline (a bridge, perhaps) and it just will not go. Rarely it will hop back into gear but I have to throw the tranny into neutral and shut the car down, then restart the car and put it in drive. It's fine most of the time, but sometimes it will buck really hard and feel like it's trying to jump gears or something, so I have to let off of the gas.
Any ideas? I've had it scanned, sensors and such checked at shops and all seems to be fine. Fluid is right on point as well.

Another problem is when idling, it fluctuates a lot. Especially when in gear, it's almost like I'm barely tapping the gas, as it just has a jump to it. The IAC valve and ECM seem to be good, could it be a bad MAF sensor? When I'm at a light, I can throw it in neutral and it idles fine. Also, I was told to run 93-grade gasoline, as the 87-grade makes it run terrible. Would that be an issue?

Any help is greatly appreciated in advance, because I'm ready to just junk the car or sell it. I'm very irritated and this is my only means of transportation right now.

 

It seems like you haven't done any searching. If you did, you would have probably found the answer:
https://maxima.org/forums/5th-genera...ma-tranny.html
https://maxima.org/forums/5th-genera...sion-help.html
Many other threads, just try the search function ...

 

I can say from experience that the transmission slipping is a sensor. The speed sensor to be exact. I was having the same exact issue. Replaced it months ago and haven't had an issue since.

 

I would change the MAf sensor and revolution speed sensor ----> and then burn some rubber..

 

coolant bypass IACV, clean iacv/tb, then idle relearn if it needs it

 

Doesn't the 2000 have a throttle cable? Shouldn't be an idle relearn...right?

 

+1 !
No need for Idle Speed Relearn, I have never done one on my car. In worst case, disconnecting the battery overnight will do the trick.

 

The iacv is still electronically controlled. I don't mess with 3.0s much, but I believe it still works like that.