[Flyingjackal456]

Hey guys... My 1998 Windstar (3.8L) is suffering from a rough warm start issue...

This has happened almost every time I stop for about 10-15 minutes...

Basically, the car was fully warmed up (I drove an aggressive 30 miles), and I parked and shut off the car. I didn't actually time myself, but I'd estimate I was away from the car for about 10-15 minutes. When I get back to the car, and turn the key, it fires right up...but immediately after turning over, the engine idles at a shaky 450 RPM, and the RPM varies up and down, I feel the car shaking and I can smell unburned gas coming from the exhaust. Pressing the gas causes the RPMs to stay up, but it still shakes, even while revving a little. The car DOES NOT stall, even in gear, at 450 RPM (I was in reverse, backing up when I noticed that the car was shaking, and I stopped while still in gear). I put it in neutral, and I revved it up a bit until this issues went away.

After the first few seconds of revving, the van is running properly, and the engine threw a P0171 (running lean)

My guess is fuel injectors and injector O-rings.... I've already replaced everything else. (Fuel Pump, fuel filter, EGR, IAC, O2 sensors, MAF, Engine)

EDIT: Just FYI, I have not replaced:
Intake Temperture Sensor
Intake manifold
Intake Plenum
Injectors
Fuel Rail O-rings
"That-rubber-thing-that-goes-from-the-MAF-to-the-throttle-body"
Driver's Seat Cushion

 

[Poppy]

VACUUM LEAK or Dirty sticking IAC

Check for a vacuum leak, and if that doesn't do it, then pull your IAC and give it a good cleaning with throttle body cleaner.

http://www.fordforumsonline.com/forum/engine-drivetrain/94-locate-vacuum-leak.html

 

[Poppy]

flyingjackal456,
I just put this up for you.

http://www.fordforumsonline.com/for...lean-your-idle-air-control-valve-iac-iab.html

let us know how you make out.

 

[electro]

By reading your symptoms, I am thinking injector leaking fuel in cylinder, causing poor hot starting.
Obliviously that dos not square up with your lean code...

http://www.fordforumsonline.com/for...cking-fuel-injector-leakage.html?nojs=1#links

 

[Boghog]

Your right on the money electro.It's called hot soak.Usually happens in warm weather.But with the aggressive driving and quick shutoff,it's a dead give away.The Higher ambient temp under the hood is causing the fuel to boil in the fuel rail.Expanding fuel will push by leak injectors and drip into cyls.This almost makes for a flooded condition.The extra fuel will set off the O2 sensor giving you a lean mixture code.This condition was more predominent in carburated vehicles,and diminished with the onset of fuel injection.But if ambient under hood temps rise,the condition can still happen.My suggestion would be to idle the car before shutdown or drive less agressively about a mile from your destination.