redwine300

Thanks Baz, I could really do with the 2 pipes that connect the plenum to the servo. The one that comes directly off the plenum and the one that comes from the servo itself, they then both join at a union on the bulk head. There are 2 more pipes that are worst for wear also, it's the 2 pipes that come off the PCV valves. If you have these in good condition I will gladly buy them off you mate. Also, if you have any clips that go with them, that would be great. Hi Tudor, I hear what you are saying. I will read up on the water by-pass and EGR delete and give it some serious thought mate. As you say, I will check all of the hoses and clips etc' after all, I don't fancy doing this again in hurry. Interesting point Eggs, once I have the plenum up on my bench, I will take a better look at the threads. Cheers. Hi Sayers, I will see how I get on when I start the re build, if I get stuck I will give you a call. Thanks for the offer mate.

Well, in a moment of madness, I went for pulling the plenum!! What a pain in the a** or what? Still, done now so there is no goin back. At least I know a little more about the zed, just got to put together a parts list for new gaskets and various pipes etc'. One good thing did come of it though, whilst removing the booster pipe work I found a large split that had been wrapped with a bit of electrical tape, could well have been leaking bady. Anyway, on the lookout for new or second hand pipes etc' so if anyone has anything that I will need please let me know. Money waiting.

Any updates?

Thinking of doing this myself. Is it a big job to get the covers off? What's involved?

Yeah, It's the one with the metal bracket. As you say, I will look at removing the bracket and using a longer bolt. I will first have to get myself out of the doldrums before I can face tackling it again. Cheers Medallion Man.

Having cleaned and set my AAI valve, I decided to replace the gasket as I suspected a slight air leak. I have removed and re fitted this a couple of times now, so was confidant all would go well. It did, until I came to tightening the last bolt, I felt a crack and the bolt started to feel loose. My heart sank as I realised that I had just stripped the thread. God do I feel Sh*t. So, my my question is, could someone point me in the right direction to a "How To" guide for removing the plenum please? preferably with pictures. Also, how difficult a first time job is it? say 1 being easy and 10 being very hard. I am thinking of helli-coiling all 4 holes. Cheers.

http://www.conceptzperformance.com/cart/image.php?II=9097 Any good? http://www.conceptzperformance.com/cart/description.php?II=9097&Car_Type=300&UID=2012121818581466.249.73.5

May have crushed a fuel line possibly?

Hi Maz, Sounds like you may have found your problem, I will try and explain my understanding of how the air regulator valve works. Fundamentally it consists of a rotating disk that either opens or closes the valve, It does this in 2 ways. Firstly, when the engine and ignition is off, ambient temperature holds the valve open via a bi metal strip so as to allow air to enter the plenum during a cold start. Thus raising the idle. Once the engine is started, a voltage of 14 volts is applied to the internal heater for approximately 5 minutes causing the bi metal strip to close the valve completely. At this point, the only valve that is responsible for the idle is the IAA valve. There is a simple check that can be done to prove that the valve is the problem. Once the engine is up to temperature, simply pinch the pipe between the IAA valve and the air regulator valve so as to close it off and you will see your RPM drop. If as you say, there is no resistance found to the heater, then it sounds like the valve will not be closed. It may fluctuate a little depending on engine temperature but basically it will need replacing. ps I should have said that the heater should take up to five minutes to close the valve completely, but the voltage will remain constant while the engine is running. This will keep the valve closed untill such time you restart from cold.

Hi Maz, I think I may have confused things here. I have referred to the Air Regulator valve as the Air Control Valve. I would like to know if the air regulator valve is working correctly first of all. Please refer to the link in my initial reply. This valve needs to have a resistance of 75 ohms and of course have a good connection. This is where you need to measure 14 volts at the harness connector when the engine is running. If we can eliminate this valve, we will be able to concentrate on the IAA valve from there on.

http://www.zedworld.co.uk/ :bow::bow:

Technically, there are 2 gaskets. One that goes between the AAI device and the plenum, the other one I refer too is the gasket within the Air control valve assembly. Maybe worth leaving this one alone for the time being as I have not yet been able to source a replacement. I made one up from 1mm gasket paper. Have you managed to check the resistance on this one yet? it may be that instead of cleaning it, it may need replacing.

No problem Maz, Glad to be of help mate. As for cleaning the IAA, I would highly recommend it. I have just cleaned and rebuilt both of the units involved on mine. A bit difficult to get to, and I would recommend new gaskets also.

Thanks Steams.:thumbup1: It's all down to your advice along with others, that has helped me understand some of the issues that beset these zeds. It is a good feeling to be in a position to then hopefully help others.

Thanks Noz, (and everyone else) for all your help.:thumbup1: Just had a bit of a blond moment by the way,:blushing: (no offence to anyone with blond hair by the way, lol) I have been checking various things with Data Scan of late, and on the connect screen it actually displays the ECU number that you guys have been referring too.:whistling: The one that was not present on the outer case. If it is safe to do so, I will interrogate the spare ECU the same way. Still can not understand why one should have diagnostic mode and the other does not though. Again, thanks guys.

Just a thought, have you tried disabling each coil pack during Data Scan so as to knock out one cylinder at a time? Maybe it could be that the plug in cylinder 3 is down. When you disable each plug separately you should see a noticeable drop in idle, at least this way you will be sure that all cylinders are firing.

I was referring to the yellow connector, the one you would disconnect up wards. This is responsible for the ECU controlling the the idle just above base idle. The connector that you remove sideways is for the F.I.C.D valve, this valve is responsible for maintaining idle when the engine is under additional load. For example, when you activate the air conditioning or when the power steering kicks in. The next unit along is for the axillary air valve, this is for aiding start up From cold. It allows a small amount of air in so as to raise the idle for a few minutes from a cold start. You can check the resistance for this which if memory serves me right should be around 75 ohms. Also, when the engine is running, you should find 14 volts at the connector.

I see, wasn't to sure of the circumstances as to when the problem occurred. As you say though, still worth checking if only to eliminate it. Have you also checked the connection at the auxiliary air control valve? maybe worth checking the resistance to that also. It has an integral heater that may have failed causing the idle to stay high. http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.335

Did you say that you have checked you TPS? Voltage should read around .42 volts and should gradually increase as you operate the throttle. If this is incorrect it can also cause a high idle.

Could be that your base idle is set too high? Try disconecting the IAA connector again and adjust your base idle via the adjustment screw. Clockwise should bring the idle down. Count the number of turns you make, as you may want to revert back if this makes no difference.

When you are at full temperature, try disconnecting the IAA connector. (it's the yellow one on mine) Does the idle drop then? If it does, what does it drop to? As Medallion Man says, worth checking the temp sender.

No problem mate. I have been servicing and setting mine over the last few weeks. (all 3 valves relating to the idle system) I have finally got her to settle at a smooth 750rpm at full operating temperature. What sort of issues are you having?

I found this link a great help mate. Worth a read. http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.335

Managed to find the box that the spare ECU came in. It has the number.. 23710-37P06 on it. does this help in identification? Question.. Out of curiosity, I would like to try the other ECU. I think it is the original one and the previous owner may have had a new one fitted to try and solve running issues. Will I do any harm by trying it? It's just that the one that is fitted does not have the ability to go into diagnostic mode as there is no integral switching assembly, just the red bulb.

Thanks for sharing Mark! Brilliant thread.