Been doing a boost leak check today and had the car plugged in to some software or other. Anyway, the one I was using had an FCID test (basically turning it on and off). I understand I should be able to hear it clicking when doing this but I can't.

 

So, before I go replacing/taking it out for a good clean, I want to know what affects that actually has on the car.

 

I know it let's the revs drop when turning on the blowers, but is that it or could it have some affect on the running of the car in anyway?

 

The reason I ask is that I can't find much wrong with the car and can't get the IAA to sit at 15, it constantly wants the move slightly when idling. Also the revs don't sit spot on and they seem to be slightly shaky if that makes any sense.

 

Not bothering me too much, just trying to make sure everything is perfect really.

It acts as a choke on a cold start or start up, it seems Lee that at the moment all your issue seem to stem from the iacv, so take it off, check the gasket when you take it off, it should stay intact or stuck to the plenum, if its in bits, then start there, it may be taking a constantly incorrect reading affecting your idle and revs.

When you adjusted the idle screw with the plug off, did it make much difference when you plugged it back in? Def an air issue if you cant get a constant reading.

Yeah, it jumped up like its meant to. Was just when I couldn't hear the FCID clicking it made me wonder if that was the route cause.

 

I still think there's an air leak somewhere but even when I was putting smoke in it today I could see/hear any leaks

I think the main function of the FCID valve is to raise the idle speed slightly so as to compensate for the additional engine load caused when the Air Con or power steering is engaged. I would let the engine warm up fully and try switching the Air Con on, you should see a noticable increase in RPM, (apprx 100rpm) same for when you rotate the steering.

I think the main function of the FCID valve is to raise the idle speed slightly so as to compensate for the additional engine load caused when the Air Con or power steering is engaged. I would let the engine warm up fully and try switching the Air Con on, you should see a noticable increase in RPM, (apprx 100rpm) same for when you rotate the steering.

 

My revs drop a little mate, here's a video I just made

 

I have another unit on an old plenum, I've taken it apart but I don't get how to take the AAC and FCID apart, so how to get to the springs etc. any idea?

My first thoughts are that the rpm is dropping due to the additional load when you switch the air con on.

This says to me that the FCID valve is either stuck or the 12 volt solenoid has packed in.

 

Have a read through this link, it was a great help to me in understanding how they all come apart etc'

 

http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.335

 

It is worth checking that the solenoid is working OK first, just apply 12v to it and you will hear it click back and fourth.

Saves time cleaning the thing only to find that it is faulty.

Anyway, see how you get on and if you get stuck give us a shout. I have serviced all 3 valves relating to the idle system on mine with good success.

So the one on the car isn't clicking (checking with some diagnostic software).

 

I have another one spare so thought I'd take it apart, give it a good clean then possibly use the one. Also serves as a practice before doing it on the actual one that's currently on the car.

 

I've managed to get the FICD apart as when I unscrewed it, the insides fell out (I've now either lost the spring or it was already missing).

 

But the AAC, how do I get the insides of that out to clean?

The link you gave (I've read it loads) doesn't tell you how to do this bit

In picture 2 it should show an exploded view of the AAI valve.

It has 2 cross head screws that bolt the valve mechanism to the body of the valve, make sure you have a very good fitting screwdriver as these screws are a pig to undo. Take the unit apart gradually as there are a few moving parts in there.

Sorry, not too sure if I've been clear here. I've taken the AAC off. In picture 2 it shows the sring the things taken out. That what I'm wanting to do but can't seem to work out how the get the spring and things out

I see what you mean.

The brass tube is held in place by a seal, it should just pull out of housing.

As for the spring and shuttle valve, these should just fall out from either half.

You may have to give each part a slight tap to free them if they are stuck.

Hope that helps mate.

They fell out of the FICD but the AAC is completely jammed. I've tried pulling it with stuff too but it wouldn't budge. Not to worry though, it's just a spare one I had

So is all of the brass tube seized within the connector side of the assembly?

Maybe worth soaking in plus gas or wd40 over night to free it.

At least that way you get to play around with the spare.

Ill take a picture of what I mean. Won't be long

Here's the pictures

 

 

 

So, there's this bit in the main unit. Not sure if this bit is meant to come out of not?

 

 

This is the AAC and I assume its the bit in the middle of here that's meant to come out but it's stuck. Been trying to pull it out with pliers but it won't move. Is it a screw in bit? If so ill use the neighbours vice again lol

 

 

Apply 12v to the terminals or 9v battery and see if the valve moves.

 

Also another thing to check, is the o ring on the base of the idle screw, if its crumbled or split, it will allow air to escape and make your revs go up and down.

 

Just unscrew it on the spare to see the o ring, but if you are doing it on the car, screw it all the way in, counting the turns till it stops, you will have a guide then of roughly where it was to re adjust on datascan, then remove the screw to inspect it.

Yeah, I checked the one on the spare I'm playing with and the o-ring on the adjusting screw was spot on.

 

I'm gonna have to go and get some wires and crocodile clips or something to try them out with the battery

Looking at those pictures a bit closer, It does not look as though the cast assembly is the same as mine.

What year/model is it from?

Mine is a UK manual 1992 tt and the one noticeable difference is the underside of the assembly, the face that sits against the gasket.

On mine it is all open and I can clearly see the base idle screw and various chambers.

Maybe there are different designs depending on make and model?

You mean this bit? I thought they were all the same. I just don't know how to get the bits I need out lol.

 

I just went out to see if it clicks when touching the battery but nothing at all. I'm assuming I'm doing that right by using both the + and - to the connector

 

As I thought, very different to mine.

I also thought they were all the same but looks as though they differ for some reason.

I have a feeling that this looks like a sealed unit. I noticed what looks like a return spring in the last picture.

If you apply pressure to the end of the rod in your second picture, can you get the thing to move in and out/back and fourth?

looks to me that the motor pushes in wards and the spring returns it.

Yeah, both the end on the main unit and on the accc that connects to it move in and out. There's a big spring inside the main unit. See here

OK, I would say that things are moving as they should and so long as there is not a faulty seal in there it should work.

Maybe worth spraying some wd40 in there and working back and fourth for a while.

Next step is to see if you have resistance at the connector.

Not sure on this model of unit but I would imagine it to be somewhere in the region of 10 ohms

I think it is a bit difficult to test the movement with direct voltage, I did this with mine but to no avail. Works great in situ though.

Not even sure if I'd put it on the car, it feels soft to press in though, like it'd have no problem working. The FICD connector isn't in the best shape though, not sure if I can just pull it off and put a new on on maybe

there are two diferent tipes of them valves ... i picked up both today just tu try my idle problems

 

Thanks rolandas. Now I'm wondering what the difference is between them and which is best

The AAC looks smaller too

the one on the left doesn`t have any nissan logos ... it might not be nissan`s