I have a 1998 BMW 528i, and the ignition is messed up, when i put the key in all it does is turns and turns "spinning"....I had to pull a fuse just turn the car off and then disconnect the battery so it wouldn't go dead....can you please help me with this problem?
A ignition is in two parts, where you put the key to turn it and a second part that is the ignition itself. Between the two parts there is a small flat pin or bar. This is where your problem is, the pin/bar is broken. You will have to replace the ignition to solve the problem.
Here are a few things to try to help you diagnois your problem.  

1.Check for corrosion on battery terminals and the fuses.   

  

2.Fuses are good - Did you check the fuse on the top of the solenoid?   

  

3. Take a screwdriver and jump the solenoid wires to start the engine. If it starts, then your starter is good. (could be a bad solenoid - but lets check some wires first)  

 Your solenoid operates when you hit the start button.  

 Your start button won't work until you turn the on/off switch on.  

 Your on/off switch only has power when you turn the key on.  

4 Use a test light to test the following:  

 Right Handlebar switch house - Test to see if you have power to on/off switch - Turn your ignition key on & off to see the testlight come on - if light comes on that means your igntion switch is good. If no light, the problem is in the igntion switch. or the main fuse to the igntion switch is bad.  

  

 If the light came on then you have power to one side of the on /off switch - test the on /off switch by turning it on and off. When switched to on you should have power to the other side of the on/off switch which is sending power to the rest of the bike which includes your starter button.  

 Test your start button with the test light by putting the test light on the solenoid - Turn key on - turn on/off switch on - push start button and see if the test light lights up. If the test light lights up that means that your solenoid fuse may be bad. It is located right on the top of the solenoid. If the fuse is good then that means your solenoid is bad. Replace it with a new one.  

 If the Test light did not come on then your starter button is not making contact and needs fixed or replaced.  

  

So follow the power with the test light until through each component until you come to the faulty one.  

  

NOTE: If its a blown fuse, check your wiring. You'll have to find out why the fuse blew and fix it or your fuse will just blow again. Could be a short somewhere, installing a battery wrong will blow fuses. Hello,  
  
Put in new batteries and try again.  
  
If new batteries did not solve the problem, the next thing to check would be the battery terminal.  
  
If
 the battery terminal is rusty, the battery power won't contact and the 
calculator won't turn on. So, use a flat small screw drive to scratch 
the battery terminal so that there would be contact.  
  
If the above
 is not the problem, the next to check would be the wire connecting the 
battery terminal to the the calculator's main board. There is a wire 
between the battery terminal and the calculator board. When the battery 
is inserted, the power from the battery goes from the terminal to the 
board through this wire. There is a possibility that this wire is cut 
in-between or is loosing contact. In this case, you need to get a small 
screw driver and carefully disassemble the calculator in order to check 
the wire.  
  
If the wire is intact, use a light brush to brush the calculator board as there might be dust on the board.  
  
If non of the above helps, then it means the calculator is dead and needs a replacement.  
  
Regards. there are so many things that can cause rough idle, can you give more information? did the car recently overheat? is there any fluids leaking on the engine? are you getting any smoke or steam from the exhaust? when checking for steam, remember to wait until the engine has run for awhile as condensation can build up in your exhaust during the night. if you cannot tell if it is smoke or steam, hold a blank sheet of paper behind the tail pipe, if it is oil smoke, then oil dots will show up on the paper.

some things you can do and check;
check the spark plug wires, make sure they are tightly connected and not chaffed, broken or burnt.
check your pcv valve for excessive oil or clogging, (it will be in a rubber housing or hose leading from your valve cover to your throttle body/carburetor)
i don't know the engine setup in that model, but if you have a distributor cap, check it for cracks and wear, also check the rotary cap.
check all rubber vacuum hoses on the engine for cracking.
if you can afford it, change the spark plugs, plug wires, rotor and rotary cap, these parts all need to be changed over time and your car is getting older now. so i have finally figured out the problem. my bios was out of date so i flashed it and now it works perfectly. re-flash bios using usb stick if you can get that far.
if not reset option and steps like clearing cmos and pins.?
new mobo or try manufacturer.. i don't think you're going to be able to fix it. can you drive the car? have it towed to a shop and get some help--you have a serious problem or several problems. how did you verify "no spark"?

if you do not have spark, you'll have to perform troubleshooting of your ignition system. 

you have a distributor, an ignitor, a coil a cap and rotor and a camshaft position sensor. if there is indeed no spark, these components will all need to be inspected. if it doesn't turn over... it can not start!!... do you mean it cranks ok .. but will not start? I had same problem it is a ground wire broken in the harness rubber boot between dthe driver door. Peel back the rubber that protects wires and you will find broken ground wire(black) add a piece of wire solder and wrap with electrical tape put rubber boot back into door everything should work. take this to a professional that can properly diagnose this problem, this approach you're taking is going to cause more problems and cost much more than if the problem was diagnosed prior to replacing parts.
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