Mitsubishi Repair: eagle talon starting problem, air fuel ratio, fuel pressure regulator

Question
I have a 1992 eagle talon tsi. I just had the head gasket, new starter, new battery done on my car. now when i try to start it, it starts very slow and takes a long time to start. unless it is cold out it starts only sometimes. my air/fuel ratio gauge is reading very lean, always in the red, my battery dies very quickly even though it is new. I'm not sure if this has anything to do with it, but my mpi fuse was blown so i repalced it. then when i put the fuse in and start the car my car will not shut off. such as i turn the car off, take the keys out of the ignition. when this happens all of the lights on my dash will come on also. When the car finally does start up the car runs great, besides once and awhile the rpm will just fall and stall then i have problems starting it again. the car has been taken to two good mechanics in my area and they can not figure it out. Please let me know  

Answer
Tim,
It sounds to me that you have short circuit in your ignition harness.  If you've tapped into your ignition harness to install different aftermarket items (like anti-theft alarm, turbo timer, or remote starter), these can cause shorts and bad grounds if improperly installed.  This will cause continuous run-ons when the key is removed and can also caused the MPI fuse to blow since it's very closely tied into the ignition.  

You can even test your O2 sensor and inspect the battery cables.  Other items like a weak fuel pump, clogged fuel filter, clogged injectors, and malfunctioning fuel pressure regulator can cause the stalling and lean mixture.  
Good luck!