Nissan Repair: Electrical fault / or computer???, fuel pressure regulator, leaky injector

Question
After overheating and cooking my motor in my automatic Nissan we replaced the motor with a motor from a manual nissan same make and model.  The car will now start, but seems to be running rich and blows black smoke.  The Mechanics don't think its the motor but seem to think its an electrical fault somewhere causing this.  When the mechanic uses his computer to try to pin point the problem our computer shows that its a manual car when infact its automatic.  Could this be the issue, do manual cars and automatic cars need their own computers or can they share?  Any suggestion....very frustrated... thanks for any advice.


Answer
Amy,

If there is a sensor that was not switched to the newly installed motor the computer would freak out.  You need to be sure all the sensors are correct for the engine that was installed.  IF the engine is running rich you might look into the fuel pressure regulator being defective.  A leaky injector or two and also, make sure the throttle position switch is working properly.  It is just a matter of checking all the old sensors on the old engine and making sure they are the same on the new motor.  If not switch them over.  Then, reset the computer and see where it goes.  Also, make sure the fuel pressure is correct.  A blown fuel pressure regulator will do what you are talking about.  Since I do not know the year or model I could not get more precise on the information.  Email me back if you need more.