Rough Idle

[NICONick]

OK, so first off, my KA-T is auto. so anyone going to get on me about it please keep it to yourself. Bought the car as an auto and working on going 5-spd

Anyways, recently, when sitting stopped the idle has gotten pretty rough, stays at 650-750 according to my SAFC II, and I get a little shaking. However, when in N or P the idle isn't rough. So, when under load, it is running rough. Not sure what would cause this?

Also, VAC is running a little higher than normal -14 as opposed to -17, but goes to normal -17 when in N and/or P. Seems to be accelerating and riding pretty normal when under acceleration, but just gets rough when coming to a stop.

Many thanks.

[Cone Killer]

First thing to do is check the ECU for codes, even if the CEL isn't on you could still have thrown code. Mine was running rough pretty much how you describe your's is. I had a code because of a bad knock sensor, after replacing it, it idled better, but still had some other issues. I had a vacuum leak at the EGR valve, and my fuel injectors were also bad. Idles very smooth now.

[NICONick]

First thing to do is check the ECU for codes, even if the CEL isn't on you could still have thrown code. Mine was running rough pretty much how you describe your's is. I had a code because of a bad knock sensor, after replacing it, it idled better, but still had some other issues. I had a vacuum leak at the EGR valve, and my fuel injectors were also bad. Idles very smooth now.

How do I check ECU for codes? or do I have to hook it up to a scanner? (95 KA24DE-T) btw

[Razi]

Google has it all.
http://www.240sx.org/faq/articles/ecm_codes_doch.htm

Also, check all your vacuum lines.