1990 300zx N/A 5 speed Idle Problems? With video.

[huntinman13]

http://www.youtube.com/watch?feature=pl ... _zlA9krR1k Tried to adjust the idle screw after unpluging the connector an the back of the IAA and there is no effect. I might be unplugging the wrong thing. the video is after it is warm.

[Zleepin]

Did yours gradually get worse & worse and end up as it is now? Right now mine does something similar, but doesn't jump as much (Or as high) as yours.. I'm thinking I just have to do a plenum swap to prevent it to getting to yours. As for the cause of this problem, I have no idea.

But i've seen some guy on youtube who installed a new plenum & it fixed it similar idle problem..

[Ace2cool]

Whoah, guys. Jumping to conclusions here. The reason a new plenum might have made a difference is either from a massive vacuum leak making the idle high, or not swapping IACV's and the new one working better. If there's no change, you might need to take your IACV off and clean it. What it looks like to me is that the FICD (fast idle control device) is stuck open, and is keeping your car at fast idle, as if were just starting. If that's frozen up, some penetrating oil could work, but you usually have to disassemble and clean.

http://s95014253.onlinehome.us/63104/157335.html

[huntinman13]

Well My check engine light came on when I was driving home from work then went off. I tried some air intake cleaner to break the FICD loose ( you can just spray it right where the intake hose comes in above the idle screw right?) with no effect. My brother is going to bring me home a can of WD-40 and I'll give that a shot. Now when I do take the IACV apart to clean it where can I get a new gasket from? I called Advanced Auto Parts and they said they don't even have it listed. Will I need to buy gasket material and make my own?( I'm gunna clean it Sunday but I have to drive the car to work tomorrow.)

[Ace2cool]

http://www.importpartspro.com/ni30oemaavag.html

Yeah, intake cleaner won't do anything for that. Hopefully the WD-40 will work, but I would actually recommend PB Blaster. WD changed their formula a while back, and it's never really been the same (it's not even flammable anymore!). PB is still great.

[huntinman13]

Yeah I have a can and went out to use it and all the air has drained out. And I live 10 miles from town so all I'll be able to get my hands on is WD-40. What about the gasket? If the WD-40 works do I even need to take it apart and clean it?

[huntinman13]

Oh and another thing, When I was driving down the road today I started hearing a Wining( Almost like a whistle). It changes with the engine speed, Is that any indicator of a stuck FICD?

[Ace2cool]

That's more indicative of a vacuum leak. The way you tell if it's a vacuum leak is by spraying some starter fluid around the engine bay, and seeing if the idle changes when you spray a particular spot. Key areas are around the plenum, any vacuum hoses, and intake piping past the MAF.

If the WD-40 works, then obviously you've solved your problem. If it doesn't, I'd try the starter fluid, as it's easier than cleaning the IACV.

[huntinman13]

Well I drove to town and bought some PB blaster, Tried and failed. then I tried the starter fluid and failed. looks like I'll be taking apart a IACV tomorrow after work. there is a Gasket that has to be replaced right?

[Ace2cool]

Yeah, that's the link I posted earlier.

[huntinman13]

Ok well I just ordered the gasket( $16.45 for shipping??) but I need it so whatever. I'll hopefully have her running right by mid-week. Thanks for the help and I'll post my results as soon as I'm done.

[Ace2cool]

$16.45 for shipping??? Where do you live?

[huntinman13]

Florida

[huntinman13]

Oh and one more thing, Now that I think back the high idle started happening when I fixed the A/C drain hose that goes through the firewall above the ECU. I had some water drip on the ECU and wiped it off, Could that have anything to do with high idle?( I'm just burning time waiting for the gasket and brain storming)

[huntinman13]

Well I ripped apart the IACV and cleaned it with some Cleaner, Was jammed up with carbon or whatever that crap was. Put it back on and no change Went ahead and ran the ECU for codes and got a 32-EGR Valve? another thing I noticed was that when I had the Clutch Booter hose off the engine would Idle around 750??? I am so confused now

[huntinman13]

Well I followed the Vacuum lines and replace some that were leaking. Took off the Air regulator just past the IACV and turns out there was a spring that wasn't attached and the connector was all corroded. Fixed that and now she idles a about 800rpm after she warms up. thanks for the help and I'm sure I'll have more questions down the road.

[Ace2cool]

Glad you got it sorted, and thanks for posting up the final fix!

[huntinman13]

Well I thought I had it fixed but now the Idle sits at 1050RPM, sometimes it will idle down to 750RPM but its rare. and sometimes when I unplug the connector from the IACV the idle will go down but when I did it tonight it wouldn't? I also noticed when I push in the clutch and slow down the idle will fluctuate between 1000RPM an 2000rpm. Also it will die if I accelerate and then slow down real quick. I am starting to think either PCV valves or MAF sensor issues.