Nissan Repair: 1997 engine turns over but will not start, mass air flow sensor, air flow sensor

Question
1997 nissan pickup xe 2.4 engine, just quit running one day on the way home from work.  The engine turns over fine but will not start.  We replaced the timeing chain an sprockets
checked the computer for codes, none related.  I have read the repair manuel inside and out.  We have fuel and spark in the plugs still nothing, Im lost is there a relay perhaps that went bad or is ecu bad?  Please help !


Answer
Edward,

Back to basics here on checking the timing first.  If the chain was replaced you need to make sure the static timing is correct.  Roll the engine over to top dead center to make sure the timing is correct on the cam.  Then, make sure the spark is occuring at the correct time.  That is, get a timing light and check for number one to fire when it is supposed to.  You say you have fuel so I assume that means that the fuel pressure is correct?  I would check this to make sure you are not getting too little or too much fuel pressure.  Another thing that will make the engine do what you say is the mass air flow sensor.  Make sure the hose is connected to the throttle body and the MAF and the clamps are tight.  If the engine gets unmetered air then it will not start.