2001 windstar rough idle at warm up,

[micib31]

2001 windstar rough idle at warm up,
start drive the van with cold engine for about 3-4 ml s ,come to a light ,stop ,van starts rough idling , if I don`t put it in neutral and hit the gas it will die ...
after that , no problem .
Hope somebody had the same problem and can help
Thanks

[dhollow2]

I have been chasing exactly the same symptoms for about a year and a half and still don't have it resolved. I don't want to hi-jack your thread but I may be able to add some information about what is going on with the engine. I'm interested to hear what others think as well. In the beginning I had intermittent lean codes on both banks which have become persistent. There are no other codes. It's fine at startup while the idle is high. Once the idle slows down it runs very rough to the point of occasionally stalling. After the temperature gauge hits normal operating temperature, it idles and runs fine. I used FORScan to look at the fuel trims and have seen the following (the scan log is at the bottom of the post):
- During initial startup and when the rough idle happens, both short term and long term fuel trims are high (20%+)
- Once the engine warms up and the rough idle stops, STFT oscillates around zero as it should, but LTFT is still at 20+ at idle, but drops to about 10% under load.

My interpretation is that it must be a vacuum leak that is significant at idle but is relatively small under load as intake air flow increases. That said, I have done everything I can to find it without luck including visual inspection, isolating the brake booster and vacuum reservoir, and even smoke testing it twice without finding any meaningful leaks. I've also tried everything I can think of to eliminate the fuel system, ignition system, and EGR as causes. The intake isolator bolt recall was done about 100K miles ago but my next step may be to replace them again. I'm very interested to hear what other folks suggest as possible causes.


The labels are hard to read but from top to bottom the outputs are: Coolant temp, IAC, MAF, RPM, Bank 1 STFT, Bank 1 LTFT, Bank 1 Upstream O2 sensor, Bank 2 STFT, Bank 2 LTFT, Bank 2 upstream O2 sensor.

[12Ounce]

dhollow2, have you tried isolating/plugging the EVAP vacuum supply? Also, if you can without a lot of expense, try swapping the MAF/IAT assembly ... just to see what happens.

[dhollow2]

I have tried isolating the EVAP vacuum line to no effect. I thought about replacing the MAF assembly but new ones are pretty pricey and it seems to behave as expected on the FORScan trace. Worth trying if I can find one at the Pull-a-Part yard.

[12Ounce]

...or a friend's working car, just as a temp donor.

[micib31]

THANK you so much for your detailed answer,
I really appreciate that.
Have also the same problems like you ......0171 and 0174 , check engine light has been on now for 2 years , the repair shop did a lot , now this with the idling for the last 3 months ,they could not find anything wrong with it (all readings are ok ,that what they told me ) those guy`s are former ford mechanics.

Don`t know what to do , will wait , because my son knows a ford mechanic and he wants to take a look , will keep you posted.

micib31

[micib31]

THANK you so much for your detailed answer,
I really appreciate that.
Have also the same problems like you ......0171 and 0174 , check engine light has been on now for 2 years , the repair shop did a lot , now this with the idling for the last 3 months ,they could not find anything wrong with it (all readings are ok ,that what they told me ) those guy`s are former ford mechanics.

Don`t know what to do , will wait , because my son knows a ford mechanic and he wants to take a look , will keep you posted .
micib31

[scubacat]

Have you replaced the inside intake bolt grommets and the port seals?

http://www.leckemby.net/windstar/windstar01.html

http://www.automotiveforums.com/vbul...d.php?t=338113

[dhollow2]

I didn't own the van at the time but I have a dealer service order showing that the 03-16-1 TSB was performed about 100k ago. I think my next step at this point is going to be to replace the grommets and gaskets. I haven't heard of people having problems after the TSB is performed but the parts aren't expensive and I'm out of other ideas at this point (other than 12Ounce's suggestion to try a known good MAF/IAT assembly). I just read the original TSB and it does say "This condition is sometimes intermittent and may not be apparent on a warmed-up engine." Hmmm, maybe repeated grommet failure isn't such a long shot after all...

[scubacat]

Who knows if they used the green improved ones or not? And even the green ones can still eventually wear out to where they're not sealing real well.

Just get the fel-pro seals and grommets; they're cheap enough. While you're in there, clean the EGR ports out real well and replace the IMRC bushings too. Even if they look ok, they're probably shot and will practically disintegrate when you touch them like mine did. (We're talking 3-4 bucks for a LOT of hassle you won't have to deal with later.)

Here's a saved shopping cart for you with everything I mentioned. (Click the "Shopping Cart" tab after browsing to this link.)

http://www.rockauto.com/catalog/rafr...708dc11ccc10ea



2001 FORD WINDSTAR 3.8L V6

Engine : Plenum Gasket
FEL-PRO Part # MS90812
Plenum Gasket Set; Upper set
$21.79 $21.79

Engine : Intake Manifold Isolator Grommet Set
FEL-PRO Part # ES72204
$8.80 $8.80

Engine : Intake Manifold Vacuum Retainer Bushing
DORMAN Part # 47099 {#F5RZ9F955AB} Pack of 5
Plastic Insert On Lower Intake
$3.40 $3.40

[12Ounce]

I must agree .... 100k miles is a lot of service for those intake manifold seals not to have failed.... even if they were the upgraded/improved seals. Do the intake "lower" and "spacer" seals as a starting point.

[dhollow2]

I got the parts after work and replaced the grommets and seals tonight. When I pulled the isolator bolts out the grommets were black instead of the green ones specified in the TSB. The long term fuel trims are now in the 3-6% range, well within the normal range, so it looks like that was the issue all along.

Even though most of the time I've spent on this was fruitless, I must say I've learned a ton about how the engine is controlled. If anyone is interested in understanding how fuel trim is regulated, what the trims should be and how to use it to diagnose problems, I highly recommend this video: http://www.youtube.com/watch?v=oRX2V6_a3dc

[micib31]

No
and thanks for your answer

[scubacat]

Great, glad it worked out. I was pretty sure that's your issue considering it affects literally every ford vehicle with that particular intake. The carb cleaner test wouldn't find that vacuum leak very well because of it being "internal" so to speak. Those were probably the last black windstar grommets still in use today; they might be worth something to a museum someday. Heh.

Anyway, nice work and thanks for the update.