Mitsubishi Repair: 95 Eclipse GST Idle Problem, eclipse gst, head gasket

Question
My Eclipse GST had the timing jump, and blew out all the valves.  Car ran great up until this point.  I had a Mechanic replace the intake and exhaust valves nothing more, and put it back together.  Now the car runs, but it is horrible with a rough idle, almost seems like it is missing,  the car smells very rich all the time, and I'm burning up plugs like crazy.  when driving the car engine seems to smooth out.  Also once the car is warm say 15-20 min of driving idle goes up to 2000.  I wondering if the mechanic didn't put everything together right, or if it is just a bad valve job.  I am also throwing a P1400 code.  Which was a map sensor.  That was replaced and did absolutely nothing.  Before the head took a crap no sensors were bad, and no check engine light.

Answer
Dan,
It may be a bad valve job or the timing belt and balance belt were not set properly on installation.  Have your mechanic (or a different mechanic) check the timing and do a compression test. Make sure compression is within tolerance on each cylinder.  When the timing jumps and the valve smash into the pistons, the top of the pistons can also become damaged and make the car run poorly. The cylinder head may have also needed to have been machined with a new head gasket so it would seat properly on the block.  Hopefully, the problem you have is simply a timing or adjustment issue, and your mechanic does not have to pull the head again.  But have them check to be sure.
Good luck!