Verify the center button is spring loaded and moves nicely. Step 10, Idle Air Stabilizer Valve / Idle Air Control Valve *If your car has a problem with its idle speed, there is a good chance your idle air stabilizer valve needs some love. The starter is relatively easy to access at this point (the starter’s solenoid shown by orange arrow); however, there are some hoses and cables that will still get in your way. Here I am checking resistance between 4 and 15. Note: You must disconnect the wires from the coil to do this accurately. I just did it this way to be quick for the photo. Ok, with your ohm meter, it’s time to check out the coil itself. Initially I was in the dark, until I happened across the BMW E34 web forums. I’m in Sydney Australia, so was keen to make local contact.
Using the wrong fluid tends to damage the injector’s internal seals resulting in external leakage about 6 months later. Not only will a poorly grounded starter struggle to turn over the engine, it will also zap away tremendous amounts of metal in your cooling system. When you get your engine from a junkyard try to get the A/C hoses with it.
Never touch an ohm meter to the wiring harness. You don’t want to throw hundreds of dollars in parts at a problem only to find out it was an air leak. Custom hose shops will be able to connect the E36 A/C hoses to your existing E30 A/C hoses.