Stall on stopping

[Pkray]

Hello everyone,

I have a 2001 explorer sport, 4.0 switchable 4wd, 212k miles. Let me begin by saying I am not a mechanic... Never worked on cars or even changed oil. I'm posting here because a lot of mechanic friends are unsure of what's going on.

The vehicle starts and runs ok for its age. After it has been run for a while, when I brake to a stop, there is a quick shudder, and it dies. This usually happens when I exit the interstate, stopping at the end of the exit ramp. It starts after that, and runs fine. This began a couple months ago, and it seems like it has gotten a bit worse, but is still sporadic. Sometimes when turning off a 45mph street it will shudder when I'm braking, but I can accelerate through it if I don't come to a complete stop. There is a noticeable loss of power when I do.

Codes read lean air and multiple misfire, but they have since I bought the vehicle(2005 with 60k miles). Cleaned the MAF about 8 months ago, cleaned the IAC(the one that does not disassemble I think), sprayed everything down with carb cleaner while running to check for vacuum leaks. Had a vacuum hose replaced 6 months or so ago. Haven't checked the PCV valve yet, that is next on the list I suppose.

The latest incident, stalled at a stop, threw it in park and started it without issue, when I shifted to drive it died. Repeated the process, died. Started just fine again, let it run for a moment, shifted to drive and it died. Repeated the process, revved it a bit in park, put in drive and it died(every time it was dying immediately after shifting to drive). Started it again, put it in reverse, it stays running, backed up about 15 feet testing the waters, put it in drive, and it drove normally. It was all side streets to my house at that point.

The MAF cleaning, IAC cleaning, were videos I watched on YouTube. The vacuum hose was replaced by a mechanic. After looking at it recently, the mechanic couldn't tell me what was wrong, but said start with a tune up and we'll go from there. I apologize if this issue has been addressed on these forums already, I couldn't find anything like it, and thank you guys in advance for any help or suggestions you might have.

Pete

 

[drdoom]

Ten years & 152,000 miles is a long time to run with codes. That can damage catalytic converters. Enough of the scolding, check intake manifold gaskets. Check IAC piping. Check spark plugs. Check fuel pressure. May even have TCC (torque converter clutch) problem. Get it on a good scanner if you can.

 

[swshawaii]

Was the replaced "vacuum hose" the PCV elbow? If not, after 212k it's almost guaranteed to be trashed. Trouble code numbers?

P0171 & P0174 4.0L SOHC's Sport/Sport Trac
http://www.explorerforum.com/forums/showthread.php?t=314670 <--- Linked

 

[JusTheUsual]

my guess would be plenum orings

 

[fast_dave]

Here's one that is often overlooked -

Pull the black plastic "filter cap" off of your IAC valve, drive around, and see if that helps.

Inside that black plastic assembly is a round felt filter, the diameter of an asperin.

Over the years, that filter can and does plug up with road & engine dust.

If you have a air blaster with a rubber tip you can jam that in the mounting hole, and blast the dust out.

Also, you can take apart the filter assembly with some patience and a small flathead screwdriver, working your way around the circumference.

BTW - is your V-6 an OHV or SHOC???

 

[Tif0ez]

Im havin the same issue, although I don't get the shudder.. its only happened a few times, but I also get the lean codes..

The IAC is the black box mounted above the spare tire, correct??

 

[koda2000]

Im havin the same issue, although I don't get the shudder.. its only happened a few times, but I also get the lean codes..

The IAC is the black box mounted above the spare tire, correct??

No. The IAC is mounted on the intake manifold behind the throttle body. It's cylindrical and has a wire connector attached to it. It may be your problem, or your problem could be your torque converter if you're experiencing a shutter before it stalls.

 

[alohamonte]

I agree on the tune up to start and have the mechanic test for vacuum leaks.

- EVAP system
- Upper Intake Gaskets

 

[swshawaii]

BTW - is your V-6 an OHV or SOHC???

Ford Cologne 4.0 L OHV V-6 (1995-2000)

Engine specifications
http://en.wikipedia.org/wiki/Ford_Explorer#Engine_specifications

 

[TomCat_Ford]

Does it start in neutral as well? Next time, try putting it in 1 or 2 (skip drive) and see if you can take off that way. I had a similar issue (stalling in drive after warmed up when coming to a stop), and it was my TCC solenoid. If I shifted to 1 or 2, it wouldn't stall.

A transmission shop with a good diagnostic tool should be able to confirm if it's the TCC solenoid.

 

[fast_dave]

IAC Valve for Ford 4.0 Liter OHV - What you see when you open the hood, located on Intake Manifold/Drivers Side.

Take note of the black plastic cap on the IAC Valve (mentioned in post #5 of this thread) as this cap is removable and within it is a felt air filter that gets eventually gets clogged with engine compartment dust.

 

[fast_dave]

Ford 4.0 Liter OHV IAC Valve - Intake Manifold Side - Pic worth 1,000 words

 

[Tif0ez]

Thank you for the picture of the black cap, I realized the part you were talking about the from the description, having changed the intake gaskets last year.. I was not aware that it was called the IAC until now.. I am amazed at the amount of information available on here, I seriously need to upgrade my subscription..
I did check and change the gasket for the IAC since the gasket kit I bought had one in it.. However, I did not know what was under the "black cap" and did not want to disturb anything that wasn't already broke..
Thanks again..

 

[mroutbd1]

Just had a similar problem with my 4.0L shutting off every time I stopped. Changed/cleaned everything that normally causes the problem with no fix. Ended up being the crankshaft sensor. I had no codes for over a month then finally got the crankshaft code. Might be something to check out.

 

[fast_dave]

Thank you for the picture of the black cap, I realized the part you were talking about the from the description, having changed the intake gaskets last year.. I was not aware that it was called the IAC until now.. I am amazed at the amount of information available on here, I seriously need to upgrade my subscription..
I did check and change the gasket for the IAC since the gasket kit I bought had one in it.. However, I did not know what was under the "black cap" and did not want to disturb anything that wasn't already broke..
Thanks again..

No problem - that's why we're all hear - for a free flow of information and experiences

Check it out - At a minimum, next time you have access to compressed air, twist off the black plastic cap from the IAC valve (some can me on there pretty tight the first time they are taken off - so son't worry about breaking anything , it's just a "friction fit).

After you take the black cap off, blow high pressure compressed air through the plastic nub on the cap that retains it to the IAC valve. The first time you do this, you will see three small (but dense) plumes of dust get blown out of the three breather slots on the backside of the black plastic cap.

That cap/filter is there for a reason - for the IAC to operate at it's peak as the piston to freely moves back and forth at a VERY high rate of speed. It needs for that filter in the cap to be clean. Hope that helps -

 

[Tif0ez]

Well, during regular oil/trans fluid check I decided to check to see if I can access the black cap to find that I do not have one.. now I'm seriously confused.. I know I am looking at the correct part, looks the same as above, but where the black cap should be, the aluminum housing was molded without it..

 

[J_C]

Does anyone know if the IAC on a SOHC V6 is supposed to have a paper gasket under it? I saw a part # for a gasket, but mine was replaced previously and had no gasket under it though it did have what looked like silicone rubber (o-rings?) and had been fine for a few dozen thousands of miles.

Anyway it got dirty so I swapped in the old one after cleaning it out, WITH a gasket I cut out of bulk material and it seems to work fine with the gasket. Should I remove the gasket for some reason?

 

[drdoom]

JC it comes with the rubber o rings shaped like an "8", but the paper should be fine too, maybe even better.

 

[Tif0ez]

Has anyone else found that they do not have the black cap/filter on their IAC??

 

[J_C]

Has anyone else found that they do not have the black cap/filter on their IAC??

All of them should have it to keep dirt out of the engine.