'92 240sx Cutting Out. Please Help???

[KaPoweredHatch]

My car started having a cut out problem pretty much right after I bought it (figures), and I cant figure out what is causing it.

I replaced:

Spark Plugs Plug Wires Rotary Button and Distributor Cap

The Problem still is there. How it works...

I start my car, Perfectly fires up every time and no hesitation even after weeks of no start in below freezing weather. It will drive fine for 5 minutes if I haven't driven it in awhile and then all of the sudden at each stop my car will idle different (mainly between 400rpm and 1100rpm). When the car starts to cut out it is always random...while cutting out in first it will delay throttle as if no fuel is getting to the engine then without changing my position on the throttle it will all the sudden kick in to the amount of fuel that should be going to the engine. Then while shifting into say second if it is still cutting out it wont cut out near as bad if I shift before 3 grand...when you get into 4 and 5 and are at much higher speeds you can still feel it cutting out but the delays are much much shorter and the cut out is hardly noticeable.

Needless to say the cutting out is never predictable. Although if I get on the throttle and reallllllly open it up (enough to say burnout, scratch second, etc) than the car will idle higher at the next stop and wont cut out until i start driving normal for awhile...

Please help me I would like to fix this problem soon and by myself. Thank you for any help in advance

[Eikon]

Here's my suggestion:

Seems to be you are having an issue with air intake. When you decelerate down to an idle, your engine is having trouble getting enough air to idle smoothly and consistantly. It may just be for a second as you let the revs down, but it is for that second that it's being starved of air. There are two components that let air into the intake manifold, you should try both...

Specifically, I would try doing two things. 1.) Remove and clean your auxiliary air controller. It's a valve system on the intake manifold that is designed to assist the throttle body in bringing in the proper amount of air to keep the engine idling smoothly. You should not have issues on startup because the engine runs on a closed loop and the intake air is modulated by the idle air control valve. But after then engine warms up it should flip to open loop.. at which time the aac should take over the fine control of air into the plenum. Click the search button and try searching AAC or auxiliary air controller. I don't have a KA engine anymore, so I can't tell you exactly where it is... When you locate it, remove it and use carb cleaner and soap and water. Make sure the gasket is solid and the spring is flexing ok.

2.) remove the intake tube that goes from the air intake tract to the intake manifold. This will grant you access to the throttle body. Use carb cleaner again and wipe off any grime you find. Test the spring mechanism on the throttle body to make sure it's not sticking. If it doesn't operate smoothly and tightly your problem will be that the throttle body isn't letting in appropriate airflow.

[KaPoweredHatch]

Thank you...

I wont be able to do any work on my car till thursday if then. But when I do both those I'll let you know if the problem persists.

Also just yesterday it did something new for me...not too different though.

When I started the car I put it in gear and as SOON as I eased out of the clutched and gave a little gass the engine starts to shake and sputter while the revs rapidly declined to about um....0rpm...well it killed it.

I started it again and left the car out of gear and it would hold a steady idle but as soon as I eased in the gas it would do the same thing...the more gas i gave it the quicker the engine would sputter and die.

It did this to me again leaving work yesterday but more times, as it only did it twice the day before.

I started my car and put it in gear and went to take off and as soon as I push the gas...it wanted to die...if i were to let out the gas before it died though it would return to a normal idle.

It was almost as if the engine were working opposite of what it should hahaha...i give gas and my revs lower. It went away after 4-5 starts though...but I even tried throttle through it and it just died quicker haha.

Thank you again and I'll try what you said.

[KaPoweredHatch]

Do you think you could get me a diagram on any of that?