Hi, I have a headache for 4 days now.  Well is about my 87 nissan  maxima
that died while my wife was dirving.  I have checked the ecm codes and
replaced a maf and fuel pump.  I have also replaced the tps and idle up
solenoids.  The car ran like it was new and then two weeks ago while I was
gone on a  trip it shut down on my wife while going home by my block.  The
battery is brand new and I had the alternator check good.  I really need
some help.  By the way the only code now that pops on the ecm is 44.
Again engine cranks but does not want to fire.  I also checked the firing
on the coil/spark plugs checked good.