My '99 5.2L has done this to me a couple of times. I go to start it in the morning and it starts then dies. I start it put it in gear. It dies. If I feather the gas while I put it in gear sometimes it will drive and then it's fine. But what seems to work nearly all the time is adding injector cleaner. I don't regularly use injector cleaner. But if it's helping, is there a cost-effective fuel/injector treatment I should be using that will extend the life of my injectors? I'm leaning towards thinking my injectors are getting clogged. The engine has 230K on the clock.

Thanks fellas!

 

I'd start with removing and cleaning the throttle body. Clean or replace the idle air control valve (IAC) and throttle position sensor (TPS).

 

I'd inspect/clean/replace the IAC as suggested and also check the battery connections. Bad battery connections or a weak battery can cause idle and all kinds of other odd issues. Taking a wire brush to the battery connections is free too if it solves the problem.