Stalling at idle, at wits end...

[TechKnow]

I have an 2000 eb explorer. I love the truck, but lately I have been having some serious issues with it...

Namely, it stalls sometimes at idle. It has been into the mechanic many times. Each time it seemed to make it a bit better, but after a couple of weeks it dies.

At first it would start right back up, but now it will not. If I let it sit for awhile it will start.

It idles a bit rough, but only sometimes.

I (my mechanic) has replaced (or cleaned):

• Cleaned Idle air control valve (first visit)
• Cleaned throttle body (first visit)
• Spark plugs (second visit)
• Ignition wires (second visit)
• Fuel filter (third visit)
• Fuel pump (third visit)
• Fuel pump relay (third visit)
• Electronic coil (fourth visit)

I am into it for a little over a grand now.

IT WILL NOT STALL FOR MY MECHANIC! Grrrr. I let him have it for a week and he drove it around, but it never died.

It seems to run fine for a week or two, then it will die over and over, then run fine again.

Here are some clues...

• It shows NO ERROR CODES
• My vents stopped working about 3 weeks before I started having issues. The blower works, but nothing comes from the vents. First it was the dash, then the rear. It started stalling after the rear went out I think. May be completely unrelated though.
  
• When my vents went out, my milage got crappy.
  
• It seems to not stall when I have hi-octane gas in it, I am not certain about this though.
  
• It usually starts up if we rock the car side to side. Yes, we do look rediculous when we do this. I feel like we should be singing Bohemian Rhapsody.
  
• On occasion when I am trying to get it to start when it is konked out it will go BAM, like it fired wrong, not a backfire, but like the engine tried to crank backward or something.

This is killing us financially and as we live in LA, it is not great to break down. Sometimes we are in places that are... inhospitable, or in the middle of traffic...

I would appreciate any ideas. If it would stall for my mechanic that would be helpful but nope...

 

[jremington59]

By Idle air sensor do you mean idle air control valve?

 

[TechKnow]

Most likely. I believe he may have just cleaned it and not replaced. From my research it seems a likely culprit...

I wonder if I should have it replaced outright...

I have fixed the post.

 

[boominXplorer]

Does it stall mainly when hot? If so I bet you need new lower intake gaskets if you have the 4.0 sohc

 

[shadowless127]

inertia switch maybe?

 

[TechKnow]

Does it stall mainly when hot? If so I bet you need new lower intake gaskets if you have the 4.0 sohc

Would this generate a code? I asked my mech about a manifold leak and he said it would generate a code & always run crappy.

I am going out now to see if it is the sohc...

 

[TechKnow]

inertia switch maybe?

Hmmmm, interesting. I haven't heard this one before.

 

[TechKnow]

yup... it is a 4.0 SOHC.

I am not sure, but I think my mech said he would see a lean bank code if it were the manifold...

 

[boominXplorer]

Leaking intake O-rings will not throw a code that I am aware of. I did a set on a 2000 mountaineer a few months ago with the same stalling issue.

 

[2000StreetRod]

check the vacuum

I suggest checking the vacuum at idle with a mechanical vacuum gauge. You may have a vacuum leak in the heating/ventilation system. You might try capping or plugging the vacuum line from the intake manifold to the heating/ventilation system. If your symptoms disappear then you have to determine what part of the heating/ventilation system is causing the leak.

 

[TechKnow]

I suggest checking the vacuum at idle with a mechanical vacuum gauge. You may have a vacuum leak in the heating/ventilation system. You might try capping or plugging the vacuum line from the intake manifold to the heating/ventilation system. If your symptoms disappear then you have to determine what part of the heating/ventilation system is causing the leak.

I wonder... I have always suspected that it was related. I will talk to my mechanic about it and see what he has to say.

I will print this thread out and take it with me next time I go.

 

[TechKnow]

Leaking intake O-rings will not throw a code that I am aware of. I did a set on a 2000 mountaineer a few months ago with the same stalling issue.

I will also bring this up. I have seen intake leaks before. I mentioned this before and he said that it would probably run poorly all the time rather than at idle/braking.

Incidentally, by idle, I mean my foot is off the accelerator. It has died on the freeway while I was coasting at about 60 mph.

That was a fun day.

 

[joe doe]

Leaking intake O-rings will not throw a code that I am aware of. I did a set on a 2000 mountaineer a few months ago with the same stalling issue.

they throw a code usually p0174 ,p0171 lean codes .symptoms would be bad cold morning idle issues that clear up as the engine gets warmer .

 

[TechKnow]

Ok, first I would like to thank you all for your help!

Here is the update... It is still stalling.

As reported before I had already:

replaced (or cleaned):
Cleaned Idle air control valve (first visit)
Cleaned throttle body (first visit)
Spark plugs (second visit)
Ignition wires (second visit)
Fuel filter (third visit)
Fuel pump (third visit)
Fuel pump relay (third visit)
Electronic coil (fourth visit)

Now I have

Replaced the crankshaft sensor
cleaned the Mass Airflow Sensor.

Still stalls. In fact it has been Stalin so long I think I am in Russia... lol

My mechanic thinks it is not vacuum as it would always run poorly and start right up after it stalled...

It will run ok for 2 or 3 weeks (the idle always feels funky though, a little low and uneven) then it will die over and over for a day or two.

When it does stall it will not start up for some time. I have noticed that when we rock the truck from side to side (okay we get desperate sometimes) it sometimes will start right back up, though this may be coincidence.

I really don't know what to do, this is bleeding me dry & it is still not fixed. Any Ideas? When I do get this finally fixed I will post the ultimate cause here as I have heard this happens to many Ford owners, but nobody ever sticks around to say what worked...

Thanks, for all of your help and I hope something good happens to you today!

 

[joe doe]

i see you have only tried cleaning the iac valve ,why not replace it?
that is what controls idle .
when it does stall do you then have a no start condition??
if so ,carry starting fluid with you ,when you come across the no start issue ,hit it with the starting fluid ,if it runs on the fluid then you know you are having a fuel delivery issue .

if you lost vent controls and such you may very well have a vacuum leak somewhere .more than likely in the engine bay around the upper intake ,there is usually a vacuum tree on the upper intake ,sometimes in a place hard to see .check there .

good luck and report back.

 

[jremington59]

i see you have only tried cleaning the iac valve ,why not replace it?

I agree with this. Cleaning doesn't always solve the issue. I'm surprised your mechanic didn't suggest this before doing all the other stuff. I would say with the symptoms it could very well be this. My IAC went once and I'd have to press the gas very lightly to get it to start when it was warm.

Did they take a pressure test and get a bad reading before replacing the fuel pump or just decide to do it?

 

[TechKnow]

I agree with this. Cleaning doesn't always solve the issue. I'm surprised your mechanic didn't suggest this before doing all the other stuff. I would say with the symptoms it could very well be this. My IAC went once and I'd have to press the gas very lightly to get it to start when it was warm.

Did they take a pressure test and get a bad reading before replacing the fuel pump or just decide to do it?

Ok... Correction. The IAC was replaced... As were the fuel pump relay and the relay just North of it.

We elimanated the possiblity of the rollover switch also, as it needs to be reset before the car will start again.

Regarding the fuel pump... He had the car for a week. I had him drive it around like it was his personal vehicle. He had a fuel pressure gauge hooked up to it and he said it was ok. However, it never died on him.

He told me to knock on the center of the fuel tank if it stalled again. He said sometimes they stick... He told me that sometimes by knocking it would jar it loose.

Sure enough, it stalled, I had my son crank it and I hit it with a mag light. Almost without fail it started right up after a knock or two...

He was up front about not having actual data and if we replaced it, it would be a shot in the dark. An aimed shot, but a shot never the less.

Additional info

Lately, when I am on the freeway, I can feel it losing power. Like all cylindars are not firing. Feels like spark, but it could be fuel. Heck I don't know. The pedal gets a bit mushy and then it will regain power.

Usually it will start acting up after that. Don't know if this is useful information or not.

I am thinking about buying a horse. At least a guy can shoot a horse in this condition...

 

[TechKnow]

If I get a vacuum tester, what do I look for & how will I know if I found it??

 

[swerneck]

I had something similar with my 5.0 V8, see thread http://www.explorerforum.com/forums/showthread.php?t=349305

Tne end was a loose vacuum line, causing the vent to stop work and also the misfire (almost stalling)

I think it's worth looking for loose vacuum lines. Good luck!

Sergio

 

[TechKnow]

Very interesting. I did check the vacuum reservoir under the fender and it had vacuum. (this was before the stalling issue) HOWEVER, I could only blow through one of the lines. I could not blow through the other one...

Shouldn't I be able to blow through both?