Engine stalls at idle--clueless!

Hi all,

My 96 Windstar (3.8L rebuilt engine, as of last year) has issues with stalling, at idle. Seems to be a pattern: I'll drive it awhile at higher speed, like on the freeway. Then, perhaps get stuck in a traffic jam...start-stop driving. Get off the freeway, and stop at traffic lights. And that's when it will act up. Engine runs beautifully until then, when it will just cut out on me while idling! Sometimes it's hard to restart.

I've taken it to the local Ford dealer and had diagnostic done (Check Engine light was on). They said it was the IAC and both IMRC motors. Replaced the IAC at home, and had another shop replace the IMRC (they tested both, and found only one needed replacing). Thought that solved it, but just found out it still acts up. No Check Engine light this time.

I've checked this Forum, and wondered if it could be the sensor wiring, as mentioned. Asked the mechanic if that's the cause, but he said that wouldn't be the case (he's the one who replaced the engine and found no wiring problems).

Help--I'm at wit's end! What else can it be? Thanks in advance.

b2

You say that when it stalls it's hard to start. What do you need to do to get it started? It sounds like this is heat related. Does letting it cool down help? Did this happen on your previous engine?

Regards

Dan

I am wondering if it is a fuel delivery issue.
Problem is, I don't know just how to troubleshoot the issue to find out how.
New fuel filter?....I would change that if it has not been done in the past year as it is routine and inexpensive.

The fuel pump relay on the '96 is inside the CCRM....another possibility, but you have to replace the CCRM (Constant Control Relay Module).
I have pictures of that posted.

The thing that makes fuel delivery issues hard to troubleshoot is the fact that the Windstar OBDII system does not monitor fuel flow or pressure, so there will be no codes or CEL to indicate that.

Another thing that I would do (after fuel filter, before CCRM or fuel pump) would be to check some of the vaccum lines.......
Check the PCV line elbow that is right on top of the upper intake manifold.....near the throttle body....can develop cracks on the inside of the elbow.
Then follow that line all the way back to the PCV valve....and make sure that it is connected, and not collapsed or cracked.
Verify that the vaccum lines to the IMRC actuators and the fuel pressure regulator are snug, and not defective.

Thank you for the replies. Much appreciated.

Yes, I've had stalling problems with the old engine as well.

Tomorrow I am taking the van to the mechanic (the one who installed the rebuilt engine) and will pass on your suggestions of things to check. Will let you know what he finds.

Hi all,

My 96 Windstar (3.8L rebuilt engine, as of last year) has issues with stalling, at idle. Seems to be a pattern: I'll drive it awhile at higher speed, like on the freeway. Then, perhaps get stuck in a traffic jam...start-stop driving. Get off the freeway, and stop at traffic lights. And that's when it will act up. Engine runs beautifully until then, when it will just cut out on me while idling! Sometimes it's hard to restart.

I've taken it to the local Ford dealer and had diagnostic done (Check Engine light was on). They said it was the IAC and both IMRC motors. Replaced the IAC at home, and had another shop replace the IMRC (they tested both, and found only one needed replacing). Thought that solved it, but just found out it still acts up. No Check Engine light this time.

I've checked this Forum, and wondered if it could be the sensor wiring, as mentioned. Asked the mechanic if that's the cause, but he said that wouldn't be the case (he's the one who replaced the engine and found no wiring problems).

Help--I'm at wit's end! What else can it be? Thanks in advance.
as I was looking for installing a speed sensor, I notice that your problem is one that I think I solved. You might check your cam sensor, my windstar was stalling out at intersections as like yours. I found out that my sensor was torqued out by the camshaft and parts were turn sideways inside of the sensor, check it out, it might be your problem!

Okay, just got the van back. Had the fuel filter replaced. The mechanic wasn't able to drive it around but did leave the enging running over an hour or so...nothing happened, as far as stalling.

He suggested that if it still does it, perhaps it's the ignition sensor (think that's what he called it). He told me that if the sensor is going out, it may not deliver a spark, and cause the engine to stall. And, usually, the probem gets progressively worse.

Well, I can't say it's getting any worse. It only seems to happen under the conditions I mentioned. Rarely does it happen otherwise.

Thanks for the tip about the cam sensor--that will also be mentioned next time, if I need to bring it back to the shop.

What a big PITA this problem is, lol!

I have same issue with 2001 windstar for 4 months now. After city driving for 30 minutes, stop the car and it won't start up for about 15 minutes. Can't hear the fuelpump whiniing sound. It starts ok after 15 minutes of cooling.

I have changed all relays ( PCM and fuelpump relay also ) changed fuel filter, also fixed the p0171/174 ( isolator bolts replacement ) on this windstar. But the stalling problem remains.

lately i found a TSB 97-24-22 for windstar stalling problem. It basically says to replace the power distribution box as moisture in it shuts off the fuelpump relay ( cost about $ 120 )

My windstar is with the dealer today to see if they can replicate the problem.

I had the same problem and checked my camshaft position sensor. The internal portion of it had been totally destroyed and rendered into dust by the deformed part that rotates around inside the sensor.

Thanks for the insight. I will have my mechanic check the Camshaft Position sensor today. I am curious, did you get any PCM computer codes in your vehicle ? Or no codes at all ?

My local dealer was able to reproduce the stalling problem yesterday. They concluded it be a fuel pump problem and changed it. I will see if this solved the issue.

But now after reading about the camshaft sensor, I am thinking it might just be the camshaft sensor that missignals the PCM, the PCM then shuts off the fuelpump using the shutdown relay.

"P0340 Camshaft Position (CMP) sensor circuit malfuntion" is the code that came up for me.

Hope this helps, my 2000 windstar suffered from a similar problem. Replaced
the MAF sensor and stalling was eliminated. Sensor was not setting any
check engine codes. Cleaned used sensor purchased from junk yard with MAF sensor cleaner before installing.

I have the same van, and had the same problem that drove me nuts for a while.
I stumbled acroosed the problem while doing a tune up on it.
There was a small formed vaccum hose (90 degree rubber elbow) on top of the engine that had a crack in it. This was causing the engine to lose vaccum at idle and stall.
I replaced it with a chunk of windshield washer hose and it has been a year without that problem now.
I hope that helps.
Thanks
Jalal

I really appreciate all the suggestions...will look into them, for sure. There's only so many things it can be. But I know now it's not the fuel filter.

While doing some in-town driving, I went to a drive-thru coffee house. As I crept along in line, sure enough, the van nearly stalled again (I say "nearly", because I was able to put it in park and rev the engine to keep it going). So we can eliminate the fuel filter.

So far there is still no check-engine light. I will try to get the van to recreate the problem and then take it to the mechanic, along with a list of your suggestions. Will check back--thanks again!

Being able to keep it running by pressing the accellerator points us back toward the Idle Air Control (IAC) that you mentioned in your first post.

The camshaft sensor that has been mentioned a few times is not an expensive part...and is easy to change......just 2 small bolts on the top of the SENSOR and an electrical connection.....NO alignment needed as long as you only mess with those 2 bolts on the top of the sensor.....the new one only goes onto the mount in 1 position.
It is the shaft and gear unit that is difficult as it must be kept in correct alignment.
I remember seeing a few posts about the plastic body around the electrical connection breaking, and causing strange problems.

......looking for an update to this. I know it's really old, but came across it and looks to be a problem I have currently. I did the intake insulator change that was mentioned, and I still have the idle stalling issue. I am thinking the IAC but not 100% I did take it off and clean it out, so I know it's not sticking, but the coil could be going in it.
Just looking for suggestions or an update on this story...

Thanks

Have you had any positive outcome with the stalling issue, I have a 2001 windstar that has the similar issues and trying to resolve.

HI
I ended up having two issues going on. The problem with stalling at idle seemed to be the idle air control. I never had a fuel pressure issue when this was happening. While trying to figure this out, my fuel pump was dying but, that posed a fuel pressure issue that I had to identify. I then changed out the IAC and haven't had the problem now for at least a week....and it was happening almost daily at least once a day.

The cheapest one I found was at Advance auto parts. If you do it online, you can put in a coupon code of P20 and get 20% off, just about anytime.
Hope this helps.

The rarest of all causes for stalling:

We all know of the popular/most likely causes for stalling: .... vacuum leaks, ....MAF, IAC, CPS, CkPS,- sensors ... dirty fuel filters, .... hi voltage leaks on ig coils, cables or spark plugs .... dirty, worn contacts on relays ....etc, etc.

But there is one other item to put on the bottom of the list, to be looked at after trying everything else: Low voltage output from the alternator. A lower, almost unmeaserable, difference in alternator output at low engine rpms can cause misery a number of ways .... fuel pump pressures can drop ... power relays can "fall out" ... marginal performing sensors can fail .... etc, etc.

HI
I ended up having two issues going on. The problem with stalling at idle seemed to be the idle air control. I never had a fuel pressure issue when this was happening. While trying to figure this out, my fuel pump was dying but, that posed a fuel pressure issue that I had to identify. I then changed out the IAC and haven't had the problem now for at least a week....and it was happening almost daily at least once a day.

The cheapest one I found was at Advance auto parts. If you do it online, you can put in a coupon code of PT20 and get 20% off, just about anytime.
Hope this helps.

Thanks for the info. I'm taking a break from solving this issue until after the new year, I have replaced the IAC already and now I have to look into the alternator and then the fuel pump. This is a big headache and I don't see myself passing this on to anyone else.

Thanks again.

The rarest of all causes for stalling:

We all know of the popular/most likely causes for stalling: .... vacuum leaks, ....MAF, IAC, CPS, CkPS,- sensors ... dirty fuel filters, .... hi voltage leaks on ig coils, cables or spark plugs .... dirty, worn contacts on relays ....etc, etc.

But there is one other item to put on the bottom of the list, to be looked at after trying everything else: Low voltage output from the alternator. A lower, almost unmeaserable, difference in alternator output at low engine rpms can cause misery a number of ways .... fuel pump pressures can drop ... power relays can "fall out" ... marginal performing sensors can fail .... etc, etc.

thanks for all your suggestions, the one that stands out the most is the alternator output. I will have my mechanic run a check and see the out come. yesterday was the first time the van actually hesitated to restart and after 5 times it cranked on, so I was considering the fuel pump. I'm also disconnecting my alarm because I find that the engine wont start until the alarm goes through a sequence or rings first. Very wierd...

Thanks again I will keep you posted.

If you have a fuel pressure gauge, attach it to the schrader valve on the fuel rail, on the pass. side just above the alt. Check it while cranking, and while running. When you turn the key over to accessory position, you should hear an audible hum from the back area of the van. If you don't hear it, try it again, without trying to start it. If you don't get the hum, you're not getting pressure to start.
Good luck! and Merry Christmas!

thanks for all your suggestions, the one that stands out the most is the alternator output. I will have my mechanic run a check and see the out come. yesterday was the first time the van actually hesitated to restart and after 5 times it cranked on, so I was considering the fuel pump. I'm also disconnecting my alarm because I find that the engine wont start until the alarm goes through a sequence or rings first. Very wierd...

Thanks again I will keep you posted.

If you're having an issue with the iac motor it should set a code. Sounds like you might just need to clean the throttle body out. Over time you get a lot of build up in there and eventually it will restrict the air passing between the throttle plate and the bore in the throttle body, which will cause it to idle rough or die when idling. I like to take the throttle body off when cleaning it, you get a better look at what you're doing. BG makes a good throttle body cleaner that cleans and lubricates, the lubricating will keep the plate from sticking when you're done. I wouldn't recommend using regular carb cleaner, cause you'll wash the tephlon off the inside of the bore. Get you some good cleaner and an old tooth brush and start spraying and scrubbing.