94 dodge shadow hard start problem

My son recently purchased a 94 dodge shadow 2.2 automatic. The car ran
but had issues with starting after sitting during the day. However,
the car starts and drives with no problems in the morning. A mechanic
friend thought initially that it was the fuel pump but later learned
that it in fact delivered fuel properly. So, he replaced the computer
and got it running. But again after sitting in the drive during the
day it would not start. My theories are that the 02 sensor is perhaps
bad the mass air flow sensor or a coolant temp sensor. Any ideas?

Thanks