Nissan Repair: 1988 nissian 300ZX engine problem, 300zx engine, variable valve timing

Question
my son ran the engine up to 6000+_ rpm the engine stalled and shut off. he restarted the engine but would not idle below about 2000 rpm. only will run if pumping the accelarater pedal until above roughly 2000. engine is fuel injected,no unusal noise or leaks, what has he done?

Answer
Stoney,

I would bet the air meter is gone bad or the intake hose has a crack or leak.  If there is no knocking the engine should be fine.  Now, the variable valve timing could be an issue if it is stuck.  Wait, after you check the air meter and intake hose check to see if the timing has not jumped.  Pull the covers on the top of the timing chains and see if the marks line up with the engine on top dead center.  i bet the timing has jumped.