03 windstar stalling

I hope someone can please help. I have an 03 Windstar that I can't move. Van will run in park fine, neutral is revving. Code was P1504 AIC which was just replaced with OEM. Still stalling when put in drive or reverse.
wiring is testing ok to PCM and intake
MAF is good
No vacuum leaks found.
Fuel pump ok, new fuel filter.

I hope someone can please help. I have an 03 Windstar that I can't move. Van will run in park fine, neutral is revving. Code was P1504 AIC which was just replaced with OEM. Still stalling when put in drive or reverse.
wiring is testing ok to PCM and intake
MAF is good
No vacuum leaks found.
Fuel pump ok, new fuel filter.

Is the vehicle acting the same as with the old IAC?

When you say OEM are you meaning it is a motorcraft IAC. Have you double checked to make sure they are the same part?? Was the gasket changed also? On a taurus forum the people have been getting the incorrect IAC from the parts stores.

Explain the revving in neutral. Does it make a difference when you step on the brake while in park??

How did you check for vacuum leaks??

Hi, thanks for responding. The AIC sensor was replaced with an aftermarket, no change and the plunger did not move when tested. (connected, not installed, turn key on) so replaced with a Motorcraft which looks identical to the old original. Also replaced gasket. Once it warms up, disconnecting the new IAC sensor will drop the rpm back to normal in neutral but van will stall when driving. Checked the wiring from it to PCM and seems fine.
Checked for vacuum leaks by feel and sound. Honestly, don't have a clue where I should be checking and how.
The van runs at 900 Rpm in park, neutral will go from from about 1100 to 2500. Stepping on the brake causes no change in park.
The van originally had the AIC sensor disconnected, ran great, new one installed and ran better then ever for about 250 miles. Shut if off, added brake fluid, turn wheels sharply to right and left to check power steering, sat for a day. Next day started and back to the stalling.

Try cleaning the MAF sensor

Thanks but it's been cleaned twice. I'm getting ready to junk it!!

It's probably a short somewhere in the connector or wiring harness for the IAC then.

http://www.rockauto.com/catalog/x,carcode,1385782,parttype,2589

Thanks for the link. I'll have to double check the wiring. It had tested okay but maybe?? shorting when running.

Have you checked for any blown fuses???

Why was brake fluid low??? Have you checked the switch on master clyinder for leaks. There was a recall on these switches but I do not remember what years.

Take a can of Car cleaner and spray around the intake manifold, brake booster, and all vacuum lines.

Have you cleaned the throttle body lately??? Was the old IAC showing a lot of carbone on it????

When you disconnect the IAC wha codes do you get???

When you installed new IAC did you disconnect the battery negative for a while, if not do so and see what happens.

Hi, have checked all fuses and relays.Sorry, meant to say power steering fluid, which was just down slightly. The AIC has some carbon but not bad for an original part. Throttle body was cleaned. When the AIC was disconnected it came up with the P1504 code (AIC) which has since gone and not come back yet. The battery was disconnected for about an hour. I then started it, idled around 900 rpm, put it in drive and idle was fluctuating from 600 to 1100 rpm. I did the brake and gas and got it to move but soon stalled. I can get the rpm's to move by pressing the brake and gas in drive. same with reverse.
When I can get it on the street, it seems to drive okay with the aic disconnected until I hit 20-25 mph, it then sputters and dies.

Have you checked the fuel pressure with a gauge??? Have the Isolator bolts been checked???How many miles on vehicle???

Do you have a scan tool that reads live data. if so look at your short and long fuel trims,

Isolator bolts have been checked. Just turned 100k. I Don't have a gauge for checking the fuel, just did the rail test.

Isolator bolts have been checked. Just turned 100k. I Don't have a gauge for checking the fuel, just did the rail test.

If you have a autozone or Oriely's close I would see if they have a fuel pressure tester you can rent, you just pay a deposit and when you return the tool you get your deposit back.

I do not know how easy it is to access the camshaft sensor on the 3.8 but I would take a look at the sensor to amke sure the camshaft synchronizer is not bad and chewing up the sensor causing the injectors to be shut off.