Stalling problem HELP

[esprit99]

I'm wondering if anyone has any input on a stalling problem with a 1997 D90 4.0 engine, all stock accept a snorkel. The truck starts and runs fine untill full warm up; After full warm up, if the truck is in park/nutural it will stall. Having the truck in drive will keep the idle up just enough to prevent stalling. While the engine is warming up the idle is 900 RPM, normal and fine, when warm and in gear 600/650 RPM and on the edge of stalling, when warm and in park the truck stalls. It seems to me to be a sensor problem. No check engine lights. Any thoughts?

[Chaucer]

I had that problem...Ran a can of BG 44k through half a tank of gas - cleaned everything up.

[esprit99]

Sorry for the ignorance but what is that.

[Chaucer]

It's a fuel system cleaner...cleans your injectors. I think the problem you might have is carbon build-up. It's expensive stuff, like $19-20 per 11 or 11.5oz container. For me and my problem (almost exactly what you are describing above) it cleared it up real nicely. Not a silver bullet, but worth a shot.

[esprit99]

Thanks for your input, I'll try it. Anyone have any other ideas.

[BarryO]

Could be the infamous stepper motor (idle air valve)?

[esprit99]

FYI removed and cleaned the stepper motor. Reinstalled the stepper and disconnected and reconnected the battery. Also running fuel injector cleaner in fuel. So far so good. Thanks for the ideas.