Strange idle connected exhaust vibration

[twoqu]

Just checked the Halford site. They are listing 2, one for £54.99, the other for £39.99. The pics should the same model - 77038 although the catalogue numbers vary. Due to lack of details, its impossible to tell whether they are indeed different or the same thing:

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_567039_categoryId_255216_langId_-1?cm_sp=Intelligent_Offer-_-Product_Details_Zone_1-_-Blank&iozone=PDPz1

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_211767_categoryId_255216_langId_-1?cm_sp=Intelligent_Offer-_-Product_Details_Zone_1-_-Blank&iozone=PDPz1

Without doubt the cheaper one is just a rebranded one of these:
http://www.ebay.co.uk/itm/US-PRO-Pen...item41644061f7

Bandits!

[twoqu]

Looking at these ISO MM, that OL reading you got actually means overload not open circuit. If the MM hasn't worked since that reading it might indicate something amiss. Bit late to get by head around what though!
Its possible that you have just blown a fuse. Depending on the contruction there are usually screws on the back to allow you to seperate the MM into its component pieces. Might be worth consulting the manual that came with it or finding a similiar models instructions. Would rather change a fuse than buy another poorer quality one!

[Greg_S]

Defintely give the output tests a try. Ive dropped you a PM with my mobile no and might be able to help you out a bit

[220bhp]

Greg,I am trying to do it at the moment,but the jumper wire will not start the test,so I am going to check the fuse and see if I have a live feed to the black connector,and an earth.
I connected the jumper wire as John suggested and double checked on your link to SJM.
I am sure I am doing it the right way,bottom connection on the black plug,as John said,
looking like an A,and bottom connection on the brown plug looking like a D.
I have not been able to blink the codes for some time on this car,but it has had vag com connected successfully by John and Alred.
I will keep trying.In the mean time, thanks for your help,its much appreciated. I may give you a call in a while if I cant find out whats wrong

[220bhp]

All fuses good ,have 12v on the black connector, but it still will not do the output test.

[220bhp]

Success.I cleaned up the ends of the jumperwire, and as best I could the connectors and it worked done all the tests and everything works.I did it twice,once with the ISV that is on the car,and once with a spare with the connector on it. The ISV opened and closed with quite a clunck. and I could see it going from stop to stopIf this means that all is ok with the ISV where to next

[newsh]

Well at least we know the ecu is controlling the ISV! Now why is it controlling it wrong?

As I posted above, your multimeter should have a fuse inside, maybe its blown? If not then take that other pos back to halfrauds, and get one for a tenner off ebay

Multimeter will have fuses inside which can sometimes blow if you connect on the wrong range or too much voltage..

Lou, I just spoke to Pete Berry. He said to check that the wires to the white temp switch on the back of the cylinder head are good, pull back the rubber boot and visually inspect for breakage and shorting.

Also check the wiring on the TPS in the same way, visually by pulling the rubber boot back.

[220bhp]

John I just took the car for a drive with the temperature sensor on the back of the head still dissconected,and it apears to make no differance to the way the car runs when it is up to temperature.I dont no if that is significant or not.You would think that there would be some differance.Maybe it is not working.How would I test it.

[newsh]

EDIT: Just posted this and saw your post above, yes I'm suspecting the temp sensor.

So the ISV works but its not controlling the idle corrctly so the ECU must be getting some wrong info from somewhere.
The warm up is controlled by the white temp sensor on the back of the head so we need to find out if this is working properly.
In oder for the ISV to control the idle the switch in the TPS must be closed.
With Vagcom we could look at the temperature output of the sensor.
Without Vagcom we can only test the wiring and maybe substitute a sensor.
Thre TPS we can inspect and test the wiring.

So lets have a look at the wiring of that sensor and also the wiring from the

[newsh]

Coolant temp sensor is connected between pins 30 and 45 on the ECU

[newsh]

I just did a test on mine. I started the car with the white temp sensor disconected with a meter across the sensor pins, the starting resistance of the sensor was about 1990 Ohms (2k Ohms meter range) as soon as the car was started the resistance started dropping and the idle was gradually getting higher. I let it do this for a couple of minutes then plugged the sensor back in and the idle immediately dropped to normal.

video here, click vv

[220bhp]

John the car is still to hot to put my delicute little hands down there to test it as yet.
But i have found another spare that I think is good so I just tested it in some hot water.
As you say IT registered 1960 when cold and then quickly dropped to 540 when I placed it in the hot water.Not sure if this is a valid way to test it ,but it would appear that it works.I will check the wireing to the ECU in a few minutes when it has cooled abit.

[twoqu]

Not entirely sure how the output tests are controlled from the ecu. I thought that the fuel pump relay pin that supplies the ISV was only triggered when the ecu sees the engine turning over/engine running. If thats the case then the ecu must trigger the fuel pump relay to supply the power and then earth the ISV or vice versa. However it does it, its probably the same for all those components.
As John as said it does seem that implies that all the wiring is ok, perhaps even the idle switch as that is used to initiate the sequence. Yet we know the symptoms can be reproduced by disconnecting the ISV! So either its not being activated or by coincidence it is activated and happens to be at a position that duplicates the same idle speed as thebypass channel. It may well be that the ISV fully open allows the same amount of air through the valve that the bypass channel does when disconnected. Also need to work out what would cause either condition assuming that the ecu is picking something up.
If we accept thats its not the ecu or the wiring then as John has said, we are left with a sensor or signal. We need to wade through them to find the culprit and sift the ones with subsitute functions. If that high idle is a limp home state, it must be a pretty serious signal. The primary source of info is the MAF I would say!

[newsh]

@ delicate little hands..

Twoqu, easy tiger

Lou, that hot water test sounds good, I'll bet that is a working sensor.

So lets do the temp sensor first, it's very important to check the condition of the wiring under the rubber boot. Pete said the wires tend to rest against a pipe of some sorts back there and get broken off inside the boot. I had a look at mine just now and you can see that the insulation is starting to crack on one of the wires where it goes into the plastic sleeving..

Then I suggest we look at the MAF and the Lambda.

[twoqu]

Well I have trawled through the info we have. That 0533 code, if we ignore the possible wiring faults, leaves only outside air between G70 and the N71. As we have discussed previously, the N75 plumbing!
Their should have been a different code if the G70 (MAF) had put it limp home mode - 0553. The only other mention of limp home is under the code 01257 which relates to the N71. The symptoms list idle speed deviation, poor drivability, idle speed 1100-1200rpm and limp home. The causes are all listed as wiring issues!
The lambda obviously plays a role in idle conditions but there is no codes associated with it.
The measuring blocks on the 3B might be affected by the artifically high idle, so not sure what we could tell from them even if we did have access, other than the coolant temp!
If the car was in limp home surely it wouldn't go to well, which doesen't seem the case! So we come full circle back to extra air.
Not sure what you did on the MM front. If we got some ISV duty cycle figures it might have been able to deduce if it was wide open or not.