89 Maxima

I got the car about a year ago and drove it from NY to MI without a problem, I got it here (MI) the next day it had a hard time starting and would struggle to go down the road. I tried to fix the problem: new cap, rotor, plugs, air filter, and tried (the best I could) to diagnose SOMETHING. Even the computer under the dash said everything was fine. Took it to the dealership and they said they couldn't find anything wrong with it. Then it seemed like once it got warmed up (winter time) it would run fine. And when the weather got really cold and winter hit, the problem went away and I went the rest of the winter and all summer without a problem.

A couple of weeks ago I was pulling out of the college parking lot (I'm not studying cars) and while I had the pedal steady my speed started to fluctuate along with my RPMs for about 1/10 of a mile. Now today I was on a road going 45mph and it happened again and so I slammed on the gas (got quickly up to 80mph) and when I got to a stop light, at idle the engine started to surge and sounded like it was going to stall. I wound up turning around and going back home.

The fuel filter seemed like it was clogged a little so I replaced that but that doesn't seem to be the case. I checked the dist. cap for cracks and ran the wires with an electric cord connected to a light and that seemed fine. Why would something start to go and then get better for a year just to return? It seems like this time it's unaffected by temp, but it still seems like the same problem. I was about 30 miles into my trip today when it started to surge and after I got home and it cooled it had a hard time starting and after that I ran it once for 20 minutes on the highway and it ran fine. ?????????? I'm lost?????

Sounds like a vehicle speed sensor or mass air flow sensor. $75 for MAF sensor from salvage yard, $500 from the dealer new. Vehicle speed sensor is around $130 new from dealer (good investment for the money).

De Max