rough idle and stalling when stopped on 2002 Isuzu Trooper

Every once in a while my trooper ( fuel injected 2002 ) will rough idle when stopped or in park then engin stalls. It restarts right away but then stalls again. It stays running after several attempts at restart when revved to 2500 - 3000 rpm for a few seconds therafter. I've had tune up - belts, o2 sensor, plugs, oil, and fuel / air filter changed but problem persist. What should I try next?

Asked by for the 2002 Isuzu Trooper
You have to check for spark, fuel pressure and injector pulse while it's having trouble.
1 more answer
I had a similar problem on the same vehicle. It was caused by a tiny vacuum leak. You can do a smoke test to verify. Replaced intake manifold gasket. Problem solved.