New Nissan Owner with Idle Issues

[Vidius]

I'm haveing an idle issue every two or three starts apart. Meaning its not an issue everytime I crank the ol girl up. When I crank it up it will run about 300 rpm to high and kind of choke out when I step on the gas (it has never died though). Then out of nowhere it clears right up. Sometimes it wont clear up until I shut it off and restart. I had a simular problem with an 88 s10 I owned and my issue was the IAC (idle air control if memory serves me correct) sensor. Does a 1989 240sx have an IAC sensor and or has anyone had this issue. This is a long time favorite car of mine but it is the first one i have owned.

Thanks for any help J.

[riaazfr1]

Do you have a MAF sensor? Maybe need to clean or change it. Also, have you tried resetting the computer?

[Vidius]

If you mean MAP sensor yes it has one and I will take a look at it. About resetting the computer do you mean just disconecting it for a while and reconnecting or having someone hook diagnostics up to it to reset it. I havent had anyone hook up to it before.

[riaazfr1]

Yes, i meant to disconnect the battery and leave it for a while then reconnect and let it idle for about 5 minutes and see if the computer learns the new settings.

I'm not familiar with the set up of the '89 240sx, but do you have an OBD port? if you get an OBD scanner it can tell you the possible codes.

Another issue could be that O2 sensors need to be changed if you have any.

I had a similar issue with my Spec V. i swapped out the stock exhaust header with racing headers and was having the same exact issue. took it to a shop and they found the problem by hooking it up to a computer. took it to a performance shop. not a regular mechanic shop. they have the tools to really look into and see what's going on within the computer.