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Old 12-06-2012, 01:01 AM
Billwill Billwill is offline
Officially Welcomed to the 'Fest
Location: South Africa
Join Date: Oct 2009
Posts: 529
Mein Auto: BMW E30 318i 1991
Originally Posted by tim96 View Post
I suspected my car was running rich because the exhaust stinks so I spent some time today exploring and testing things.

It is good to take a good look round every now and again in my opinion, you notice things, I found a broken cable tie causing my radiator hose to touch the fan, a hole in intake boot and the hose clamp attached to my fuel pump was only half tight. Anyway..

I tested my air flow meter, idle control valve and coolant temperature switch against the repair manuals here is what I found.. (motronic by the way and I have the three wire idle control valve)

When you disconnect the idle control valve the idle should raise to about 2000 rpm = when I did this at operating temperature my motor stalled, have not tried this cold yet, will update

Between the inner and outer terminal supplying the idle control valve there should be about 10 volts = I have about 10 volts on one side and about 3 volts on the other, this is true when motor is hot an cold

Idle control valve should be half open with ignition on at operating temperature when all accessories are off = mine is shut

Coolant temp sensor should be 2200 - 2700 ohm at 20 degrees Celsius and 300 - 360 ohms at 80 degrees Celsius = I got 2,100 ohms at around 20 Celsius (close enough) and 208 ohms when I shut of the car after a 20 minute drive. Measured it again about 10 - 15 minutes later when temp gauge was just above 1/4 (however accurate the temp gauge is) and I got 270 ohms........So not 300 - 360 as specified but then maybe there is a 90 Celsius thermostat in it? or heat in the engine bay made it above 80 Celsius. What do you think?

Sidenote Why do water and leaves end up under the battery (battery in engine bay) If I was missing the weather strip below the windshield that seals against the bonnet I could understand but I am not missing it

Also similarly, why is the wiring running behind my coolant overflow tank damp and wet, the tape that holds the wires together is rotting, same with the wiring behind the headlights where the air intake sits. It has been raining recently, but is this normal?
The exact specs. of the Blue temperature sensor are not critical...your sensor seems to be working fine!

Have you checked your Throttle Position Sensor is working fine!
You need to measure this at the ECU plug.

Also check for air leaks around the whole intake area.

The only way to test the voltage going to the ICV valve is with an oscilloscope as the ECU sends Pulse Width Modulation pulse along the ground leg of the ICV to get the fine posistioning required.
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