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Discussion Starter · #1 ·
I have a problem with lumpy idle when standing in drive and idling the car actually bounces slightly it stops bouncing when neutral is engaged . I have checked for any air leaks but all seems to be ok .Apart from this the car performs well if a bit thirsty. It smells rich when idling. Can any one give me a clue what could be the cause.:eek
 

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im having a very similar problem to you at the moment. My post is a couple down from this one.

It could be you ICV (idle control valve). Its underneath the inlet manifold.
 

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Discussion Starter · #6 ·
Bournemouth is bright and sunny today but very very cold. I found a cracked and worn out rubber cap designed to blank off a metal tube on the underside of the throttle butterfly valve assy. i re blocked this tube . Got very excited but when reassembled the same fault is there . there is a small square flange on the side of this assembly that has two small water pipes leading to it and a ventilator tube leading to the rocker cover box ., all in reasonable condition ,What is the function of the two small water circulation tubes .I have cleaned the throttle control valve with switch cleaner and checked the resistances over the three terminals and these seem to be in line with what the book says . The switch under the butterfly housing has a round connecter with a number of terminals in a circle , is there any way of testing this item as i am a bit suspicious that this may be the cause . It does click when opened slichtly well it did but i have turned the top screw in to increase the the tickover to make the symptoms less and the car more drivable. I have had the airbox off and cleaned it all out and the valve that moves as the air is drawn is moving very soothly and all is ok with the electrical connector on the side and it has a new air filter. When ticking over it smells very rich.
 

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What is the function of the two small water circulation tubes.
They help stop the throttle body from icing up on cold mornings, when you drive the cold air can play havoc with the running in cold countries

When ticking over it smells very rich.
If you can find no air leaks at all then other things it could be are air flow meter,engine temp sensor or lambda sensor(most likely if it's original one).

It will be worth getting the codes read for the DME, as there may be a code stored. Can you get access to a scanner?
 

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Discussion Starter · #8 ·
Thank you for your sugestions i will try the local garage who specialise in BMW to do a scan for me regretably they charce £40 +vat. You don't think that the thtottle position switch below the butteryly housing could be the cause . and i presume if the engine temp. sender was out this would affect the temp gauge on the dash board .
 

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Thank you for your sugestions i will try the local garage who specialise in BMW to do a scan for me regretably they charce £40 +vat. You don't think that the thtottle position switch below the butteryly housing could be the cause . and i presume if the engine temp. sender was out this would affect the temp gauge on the dash board .
What garage is that?
 

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Discussion Starter · #10 ·
I have talked to the local BMW repairer and he tells me that on this model of motronic readouts tell very little and did not advise involving the cost . This car does not have an oxegeon sensor it has a pickup on the crank pulley, does not have any mixture adjusters on either the throttle body or on the outside of the MAS the idle control valve has three terminals The switch fixed to the throttle body under side is round and has a number of terminals in a circle this is different to the illustrations in various places that show this switch as having three terminals in oblong formation .My system does not respond to the self test diagnosed proceedure . I think this may be a motronic 1.1 but i am unsure . I have tested the tem. sender and obtained 5ohms cold 300ohms hot The distrtibuter does not have any vacume advance .Over time do valve clearances tend to open or close like they do on a diesel.
 

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I have talked to the local BMW repairer
What garage did you talk to? :confused

And he tells me that on this model of motronic readouts tell very little and did not advise involving the cost.
They must be expensive then, fortunately I know someone who is not :)

This car does not have an oxegeon sensor
It does, number 20 here http://www.realoem.com/bmw/showparts.do?model=HD62&mospid=47375&btnr=18_0172&hg=18&fg=10

it has a pickup on the crank pulley, does not have any mixture adjusters on either the throttle body or on the outside of the MAS the idle control valve has three terminals, The switch fixed to the throttle body under side is round and has a number of terminals in a circle, this is different to the illustrations in various places that show this switch as having three terminals in oblong formation. My system does not respond to the self test diagnosed proceedure.
All correct :thumbsup

I think this may be a motronic 1.1 but i am unsure.
It's Bosch M3.1 :)

I have tested the tem. sender and obtained 5ohms cold 300ohms hot
It should be 2290 - 2700 at 17 - 23.C
or
290 - 364 at 77 - 83.C
The distrtibuter does not have any vacume advance.
Correct as it has no dizzy. :)

Over time do valve clearances tend to open or close like they do on a diesel.
No, hydraulic buckets :thumbsup
 

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Discussion Starter · #12 ·
im having a very similar problem to you at the moment. My post is a couple down from this one.

It could be you ICV (idle control valve). Its underneath the inlet manifold.
I have detected a hissing sound behind the rear of the inlet manifold up till now i have put this down to being a normal engine noise however using a short length of garden hose i have located exactly where the noise is coming from , its just forward ot the rear most manifold securing bolt so i ran a few squirts of oil fron an oil can at this spot and lo and behold clouds of smoke came out of the exhaust .I have now ordered a new gasget and a set of injector seals --- hoping of course thyat it is not a faulty manifold.
[email protected]
 

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I have detected a hissing sound behind the rear of the inlet manifold up till now i have put this down to being a normal engine noise however using a short length of garden hose i have located exactly where the noise is coming from , its just forward ot the rear most manifold securing bolt so i ran a few squirts of oil fron an oil can at this spot and lo and behold clouds of smoke came out of the exhaust .I have now ordered a new gasget and a set of injector seals --- hoping of course thyat it is not a faulty manifold.
[email protected]
It could well be my problem, ive yet to fully investigate mine due to other work on the car, but it would make sense! Gaskets are a hell of a lot cheaper compared to ICV's so your lucky!! Cheers for the pointer mind!...:thumbsup
 
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