Expert: Josh Fields - 12/30/2005

Question
Josh I sent a message to you earlier about my sons 84 bmw and how it doesnt seem to bog down after starting out (no power to get out of the way) I have chaged plugs,plug wires,cap & rotor also checked the coil (shows good) but still acts like its getting to much gas or flooding when shifting from first to second and so on unless i baby it and shift before rpms reach 2000. any other Ideas?.  Thanks for your help.

Answer
How long has it been since the O2 sensor was changed?  This sensor compairs the oxygen level in the exhaust compaired to the outside air and adjusts the ammount of fuel to inject into the combustion chamber.

 This "could" have an affect although I've never seen a bad 02 sensor give problems as bad as you are stating.

 Also check your Air Flow Meter (AFM).  Its a little grey box that is inline with the intake boot.  It should be right behind your air filter.  This AFM measures the ammount and temperature of the air coming into the engine.  This meter also tells the injectors to let more or less gas (basically) come into the system.  you can test to see if it's working correctly by starting the car, then unplug it to see if it makes a difference.  I have had cars run with it unplugged, but as soon as you apply any throttle the engine will go dead.  This sounds similar to your problem.
 So if you unplug this sensor and it makes no change in how the engine is running then this is your problem.  Make sure the connector is making good contact with the prongs on the AFM.  
 I would try the AFM before the O2 sensor, because I feel that the AFM is more likely to be the culprit.

 let me know if this helps,
 Josh