Hi all,
I have a new 1998 Nissan 200sx that I just bought and I already have a problem I am hoping you could help me with. The Idle doesn't always stay steady and today going down the highway, the car died on me. It was hard to restart and took giving it some gas to get it going. I also noticed that when I am sitting still in neutral, I can rev the engine up to 2000 rpm, take my foot off the gas, it falls to 1000 rpm and then rises back up to 1500 rpm on its own before falling again. I would greatly appreciate some fast help as I am trying to get this fixed before a trip this weekend.
Thanks,
Jim Dager

 

I had a 1984 Nissan 200sx that did the same thing and it was the ecu that was bad. Somone else had told me there is a barometric pressure sensor on the ecu that actualy goes bad , when the pressure is low it runs great when it is high it will do all sorts of reving and then stalling. I changed the ecu and it ran fine for a long time after.

 

check for vacumm leaks cause that can cause an idle problem (unmetered air) and also check the IAC for leaks or malfunction, and also check to see if your pcv valve is stuck.

 

run injecter cleaner in my 96 200sx I had the same problem I ran injecter cleaner and it straightened right up