2001 windstar stalls when a/c is on and in drive position.

[aviacionlight]

Hi. This is a wonderfull site thanks god i found it.
My windstar 2001 was runing almost fine, six months ago the check engine ligts on and 0171/0174 codes were present but stills working fine until the last two months, first start to hesitate at all speed ranges, check the codes again on auto zone and the trouble was two bad spark plug wires, i change it all wire set for a new one and new spark plugs too (autolite double platinum) at this point every thing looks ok but two days later the van star to run rough, here begins the nightmare.

When engine starts runs ok but when change to drive or reverse the idle speed becomes crazy up and down and go worst when a/c is on (on park position the engine runs almost fine) everything looks like the iac valve was wrong and i change it (dealer recomendation) but the trouble stills.

I try everything:
Remove the intake cover
Clean the egr ports
Check the egr valve
Clean all the sensor conections
Check all the vacum lines
Clean the maf sensor
Cange the battery
Change the iac valve
Change the pcv valve
The dealer says they do the tbs for the 0171/0174 codes but still fail.

Do you have any idea what's wrong?????????????

The other trouble is the transmision...... one year ago the van starts to change from 3 to 4 at very low speeds i use the o/d buton to correct the problem but now changes from 3 to 4 and hesitates to much goin back and fort, (no o/d light blinks) since the last year i note a burn smell on the engine compartement could be the transmision?
It is a relation betwen the engine stall trouble and the transmision?

Pd. Sorry for my english

Angel Galicia
Monterrey, Mex.

[12Ounce]

If the dealer did the TBS work for the codes P0171 and P0174 ... then why are they not "standing behind their work" (making everything good)?

Did you pay them for this work? ... or was it paid for by previous owner?

[aviacionlight]

Hi 12 ounce. The tbs was paid for the previous owner 2 years ago and was working ok.

This windstar is gone me crazy.

Any help.

[fdunford]

Sounds like a well hidden problem. You hit the obvious already like the IAC.

I am thinking it may be worthwhile to take the TPS (Throttle Position Sensor) off and ohm it out. If working, it will slowly sweep from a low ohm reading to a high reading. If there are problems with it, the reading will suddenly jump to a high/low reading.

if you have access to an ohm meter you can do this easily, thus, no need to change the part without verifying it as bad first.

[lewisnc100]

Gotta say my first thought was TPS as well, when you combine poor idle/stalling with the transmission appearing to hunt between gears my first thought would be the TPS. Had the same thing with my Nissan, stalling at stops, hunting between gears and traced it down to the TPS. Luckily on my Nissan the TPS is adjustable, on your Windstar its not.

Did they also check the fuel filter and fuel pressure?

[DRW1000]

If I read the original post it sounds like it currently has the 171/174 code. This normally implies a vacuum leak or a problem with the MAF readings.

Since you replaced the MAF I would concentrate on vacuum leaks. Vacuum leaks can be hard to track down. Look for any looseness in vacuum lines as well as cracks.... I know you said you checked them but I would try again.

The transmission problem is most likely not related.

[12Ounce]

I agree with DRW, focus on the vacuum leaks first.

It's possible that the TBS was performed with the original design (black)isolator bolts ... and over time, they have also failed. I would inspect the isolator bolt area and be prepared to replaced them with current design (green).

In fact, I have had this problem ... that is, I made the repair using black sealed bolts ... that's what was available when I made the first repair. Had to do it all over again!

[aviacionlight]

This weekend gone to take the engine naked and start again wire by wire, line by line and conetor by conector hope this work.

By the way the trouble whit the transmission continues, when driving on last gear and slow the speed the transsmision dont shift the gear down to 3 or 2 i have to give full trotle and the gears go to the right position, any ideas?

Thanks.

[lewisnc100]

Aviacionlight, what's the status of your check engine light and codes currently? Your original post seemed to indicate you had the codes 6 months ago and then had repairs done. Is the check engine light still on and if so what are the current codes?

[davwha]

Check the Vehicle Speed Sensor (VSS). When the car is in drive, the computer uses input from the VSS to control both engine functions (such as fuel and timing advance) as well as transmission shifting.

[aviacionlight]

Lewisnc100 still the same codes 0171/0174

Davwha were is located the VSS?

More bad news yesterday the o/d light star to blink, the oil level was ok.

[lewisnc100]

Also make sure you check the fuel pressure regulator vacuum line which can cause those codes as well, didn't see that in your list. Here's a pic:

http://groups.msn.com/FordWindstar/s...oto&PhotoID=24

[davwha]

The VSS in mounted on the transmission case. It is behind a small transmission heat shield above the right driveaxle. It has a 2 wire connector.
With the connector disconnected, there should be 1.5 volts between one of they wires and ground with the key on and the engine off.

[aviacionlight]

Hi Davwha.

The right drive axle is on the passenger side?

thanks.

[aviacionlight]

Update.

New codes found it: 0156, 0174, 305, 0715, 1401

where can i find a list of codes?