E30 Zone

Hi all, my car idles at 800rpm, but it is a bit lumpy, any suggestyions on how to remedy this - thanks

Standard reply to this is to clean your ICV before anything else. It's a very common complaint.

RevBillyG wrote:Standard reply to this is to clean your ICV before anything else. It's a very common complaint.

Nah, that's for inconsistant idle.
Standard answer is blue temp sensor.

You know, I've really got to find out more about this blue temp sensor. I'm getting a replacement AFM soon to try to sort out my strange idling (it was suggested to me by BMW of Hook) but I've not looked into the temp sensor.

Where is it? How do I test it?

cheers, where can i find the temp sensor and also it seems to run a bit rich aswell, I have tried a new air flow meter but it's the same so I have disregarded that, I have cleaned the ICV aswell thinking that may possibly help.

being fuel injection would i be right in saying that I could reset the ecu? if so, how? cheers

If it's running rich, that points even more to blue temp sensor.
Rough idle, to the point of stalling sometimes and running rich were the two symptoms my (very) cheap daily driver came with four years ago.
Now, if you tell us what engine you have, we'll tell you where it is and how to test it.

i have a 1.6i m40 1990...

Hmmm! That's the worst one to get at.
It's located just below inlet ports 2 and 3. i.e. 1/2 way back the left side of the engine under the inlet manifold and is not the easiest place to get.
To test it you measure the resistance between it's two terminals.
These figures are actually measured off a good sensor:
Cold water : 3400 ohms
Hot water (from tap) : 980 ohms
Very hot water :306 ohms

If your sensor is faulty, you will get higher readings than these.
In the example I mentioned in my previous post,(also an M40), the readings were about double.

cheers Brian much appreciated I will go and test it now, cheers again

i have the same problem with my 89 325 i, its pretty lumpy, and shudders below 1500 rpm off the throttle, my air flow meter is reading up and down resistances as the flap is opened to its fully open position - i believe (and hope) that this should solve the problem.

Brian Moore -should that not work where is this temperature sensor for my motor?

Cheers

Yours is much easier to get at.
Top front of the engine on the thermostat elbow. ( The bit with the air bleed screw on it).

you guessed it ,mine has the same fault,idles at about 500rpm
hot or cold and stalls,cleaned out the idle control valve but still
the same.what are the resistances for an 88 320,i think i know
where the sensor is up front on the head?

any help would be welcome

As far as I know, (but I've never checked), the blue sensor is the same on all E30s.

well... I'm guessing the blue temp sensor is inside the cave made by the inlet pipes, I didnt get to it but found if I blocked off a loose line which was sucking air in it was dandy, so I'm happy now! I really need to see where this line goes to though :S

still running a bit rich though?

Brianmoooore wrote:Hmmm! That's the worst one to get at.
It's located just below inlet ports 2 and 3. i.e. 1/2 way back the left side of the engine under the inlet manifold and is not the easiest place to get.
To test it you measure the resistance between it's two terminals.
These figures are actually measured off a good sensor:
Cold water : 3400 ohms
Hot water (from tap) : 980 ohms
Very hot water :306 ohms

If your sensor is faulty, you will get higher readings than these.
In the example I mentioned in my previous post,(also an M40), the readings were about double.

hi just wanted to confirm

i tested the blue sensor on my e30 and got the following results

Cold water : about 3100 +- ohms
Hot water (from tap) : warm water in a bowl, was decrementing got bored took it out,
Very hot water :operating water temp 180-+ ohms

is this a duff sensor? compared to brianmoores values? car does run rich, idles high.

thanks.