the engine stalls at idle?

Has the check engine light come on? It sounds like a vacuum leak or the IAC is bad. These guide will help us find out the problem

https://www.2carpros.com/articles/stall-at-idle

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

Please run down these guides and report back.

Yes, the check engine light has been on for awhile now so I changed the IAC and that fixed it thank you.

Good to hear, please use 2CarPros anytime we are here to help.

I have a problem where while driving at a low speed with very little to no throttle, slowing down, or trying to stop, my RPMs will waver and drop. Sometimes the engine will stall. I will have to restart the engine while driving or stopped. Sometimes I can tap the brakes or gas and the RPMs will go back to normal. I have a code on the dash. I have pulled it. It talks about something running lean. This points to Mass Airflow Sensor. I have removed, cleaned, and reset the system twice now. The problem was temporarily fixed the first time. The problem got worse (aka happening on a regular basis now). I was wondering if there is a way to bypass or fix this problem, or if anyone knows what exactly is causing it. I might also have a bad catalytic converter. Could that be causing my problems. I greatly appreciate any assistance.

Thank you ahead of time!

A lean mixture can also identify a vacuum leak. Have you checked for that?

I have not checked for a vacuum leak. I'm not necessarily sure how to go about that. Could that explain how my MAF sensor keeps getting dirty and clogged? What's the best course of action for checking for vacuum leaks?

Thanks

Is the MAF getting clogged with dirt? If so, is the air filter good? Also, there are several vacuum hoses that are on and around the engine. I would recommend checking for any broken, disconnected, or dry rotted ones.

As far as the MAF getting dirty, do you live in an area where there is a lot of dust and dirt?

I don't live in a dusty or dirty area. I will take a look to see if i can find any dry-rotted or weathered hoses. I'll also check for any disconnected or broken hoses. The MAF sensor seems to be getting clogged with grimy dirt. The air filter i good. I'm not sure what is causing the ridiculous build up.

Have you ever noticed any oily substances on the air filter or in the intake where the MAF is located? Have you ever replaced the EGR valve? I'm starting to think the engine may have blow-by and allowing oily air from the engine is making it way through the PCV and into the maf.

Let me know. Here is a little check. With the engine running, open the oil fill cap and see if there is a lot of pressure coming out of it.

Let me know what you find.
Joe

Yes...I have noticed that the dirt is usually grimy or oily. I wasn't sure what was causing that. If I do have a blow-by problem, how do I fix it?

I have not replaced the EGR valve because I have never pulled a code referring to that problem. I had another vehicle with that problem before.

I will try that oil pressure test you were referring to. If there is a lot of pressure coming out, what does that tell me?

I am definitely not a mechanic. I have worked on cars a little bit in the past, but it has mostly just been maintenance work.

I appreciate your help, Joe.

-Chad

Not all the time but a good majority of the time when I go from reverse into drive my vehicle will shut off. So this is what happen, I put it in reverse I backup put my foot on the brake shifted into drive take my foot off the brake the car shuts off . I have noticed that if I quickly put my foot on the gas and give it a good push send the car may not shut off sometime. I haven't had any other problems with the car except for a cranking sound which could be a whole other problem, I don't know.

Chad, The EGR valve won't cause a code. It should be part of a tune up. As far as checking if there is a lot of pressure coming from the oil cap when opened, that will tell me if there is excessive blow-by. What causes that is worn piston rings. When the piston builds compression, bad rings allow compression to escape into the crank case. If that is the problem (which would be odd at this mileage), the only thing you can do is replace the rings.

Let me know what you find.

Hi,

The component that maintains idle speed is called an idle air control valve. It is located on the throttle body. If this isn't working properly, it could cause the engine to stall.

Here is a link that explains how to service one. Take a look through this and see if it is something you could do. If so, when the IAC is off the vehicle, inspect where it mounts for carbon build up and dirt. Also, see if the pintle on it moves a bit when the key is turned on and off. ( you will need a helper to do that)

https://www.2carpros.com/articles/idle-air-control-valve-service

Here is a link that shows in general how one is replaced:

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

Now, if you confirm that it isn't working, here are the directions specific to your vehicle for replacement:

_______________________________________

1998 Ford Truck Explorer 4WD V6-245 4.0L SOHC VIN E EFI
Removal and Replacement
Vehicle Powertrain Management Fuel Delivery and Air Induction Idle Speed/Throttle Actuator - Electronic Service and Repair Removal and Replacement
REMOVAL AND REPLACEMENT
REMOVAL


Typical Idle Air Control Valve

Pic 1



1. Disconnect the Idle Air Control (IAC) valve electrical connector.



pic 2



2. Remove the IAC valve.
1 Remove the two bolts.
2 Remove the IAC valve.
- Discard the gasket.



pic 3



INSTALLATION

NOTE: Install a new IAC valve gasket.

1. Install the idle air control valve.
1 Position the IAC valve.
2 Install the two bolts.
3 Connect the IAC electrical connector.

_____________________________________

Let me know if this helps. Also, let me know if the engine has a rough idle at all times.

Take care,
Joe

Sorry for the delay on my response. I have been extremely busy for the past couple of weeks. I did get a chance to check the cap for pressure build up. I didn't find anything out of the ordinary. When I pulled the cap off, while the engine was running, i put my hand over the fill hole and didn't really feel any pressure.

I don't know if this helps or not, but when I have the a/c running, the problem occurs much more seldom. The a/c running seems to help. I'm not sure how that works, but it's an observation I made.

Well, I hope you might have some more insight into this problem. I greatly appreciate your assistance.

-Chad

What should I check first? When it comes to a stop it stalls. If you start it and let it go it ends up stalling.

I need to know if the check engine light is on? If it is then call around to your local parts stores and see if one does a free scan. Have them scan it and write down what codes are found then have them clear them. Get back to me with what you find. If the engine light is not on then we will go from there.

Yes the check engine light is on. It was a truck left for dead so I put new plugs and wires in and it works fine with your foot on the gas. Once you take it off it starts chugging then stalls.

Ok if the check engine light is on then call around and find out if one of your local parts store will do a free scan and get back to me with what codes are there. Have them clear the codes after you get it scanned and write the codes down. Get back to me with the codes so we can try to see what the truck is telling us is wrong, and we will go from there.

I got the codes, which said the I had an EGR problem (which has been replaced), misfire on plugs 4-6 and the engine was running lean. I have also changed the IAC valve. What's next?

My truck won't start. Each time I start the truck it just shuts off. As long as I press the gas it will stay running, but if you take your foot off the gas, the truck will cut off. Please help.

How low can you let the engine RPMs get? if you can get right down to where the engine should idle your idle control isn't funcioning properly. If you have to keep the RPMs higher than it should need to be then check the injectors and elecrical systems like the map or maf sensors.

1999 Ford Explorer automatic transmission with 60,000 miles. The car after 45 minutes of interstate driving stalled when stopped at exit. The stall felt like I had taken my foot off the clutch of a standard transmission. The engine started and ran well in park and neutral, but when put in gear, immediately stalled. The car would run in reverse, but not well. No previous problems.

Any thoughts?

your tourqe convertor might need to be replaced

How can you tell if its the torque converter and what kind of price should I expect.

For the past month or 2 whenever i start my car in the morning the car and engine starts shaking and the rpm starts jumping up and down then the car cuts off. After i start the car up a couple more times and it gets warm its fine. But as of 3 days ago, while i was driving the car started to rev but go no where, it wasnt changing gears properly. It feels as tho the tranny was slipping. Now its to the point where i cant drive the car. I was also told by previous mechanics that my transmission fluid was dirty or burnt. Is my tranny done and how much would it cost to fix or replace?

Based on your description, it sounds like the clutches are bad in the trans. At first, they can cause a chatter then begin to slip and eventually the car won't move. In gear it will feel like neutral.

Is that what is happening? If so, it will most likely need a general overhaul. Usually, the cost is around 2500.00 based on where you live.

Let me know if you have other questions.

my 99 ford explorer will start and have power but dies. it continues to have power if i give it gas and will drive if i am conitnously giving it gas but will die when i let off of it. eventually it will kick in, usually after a few seconds of holding the gas in, but lately its been taking longer. the idle runs really low, does this have anything to do with it? and if it does how do i change fix?

First thing you need to do is have the codes read, Autozone does it free, Post the results with the code number(s). Even if the service engine light is not on, there should be freeze frame data stored.
If it won't make it to Autozone, buy a cheap scanner, they can be had for 30-40 dollars, a good investment, since they cover all cars sold in the USA from 96 on...
If the light is blinking, it means possible damage to the converter...service it right away!

When I step on the gas my truck is fuine but when i let off the gas my truck's rpm goes under 1 and then dies on me we've tried a throttle postioning sensor but it just got worse.

Couple thoughts...

First see if any codes are stored in the computer.

Check for vacuum leaks. The 4.0 had a problem with leaking intake gaskets.

IF no codes, I have come across problems with the Torque converter solenoid being broken out of it retaining bracket.

I have a 1999 V6 Ford Explorerer XLT with 143,000 miles. A little over a year ago, I started it up and it stalled out. The car continued to stall out unless I kept my foot on the accelorator (in other words it would not idle). I drove it to work which is about 7 miles away. i then returned home after work and i was going to bring it in the shop the next day. The next morning I went to start it up and it was fine. A couple of months later it happened again. It then stopped again, but i still brought it to a repair shop to see if they could diagnose the problem. they ran a full diagnostic test and everything came back fine. they didn't know what the problem was. This has now been happening every couple of months for over a year. The most recent time it happened it went on for over a week. I wouldn't mind but it is dangerous because you have to keep your foot on the accelorator and the break at the same time while driving. Do you have any ideas. Thank you in advance.

is it harder to start when it is cold outside?

how bout when it is hot outside?

will it start right back up after the car is shut off after warming up?

recent tune upon fuel filter or pump?

It seems as though the weather conditions have nothing to do with it at all. It has happened in the summer and winter. I usually don't drive my car for more than 30 minutes when this is going on and somtimes it goes away as i am driving and other times it seems to go away overnight. I replaced the fuel filter a couple of months ago but it has happened since then. I know this doesn't help much, but there really isn't much of a pattern when this happens. i appreciate any help.

It stalls out when put into gear. Why

First eliminate all vacuum or air leaks in the system. You may have a bad IAC ( idle air control) but try cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.

The engine turns over, but as soon as you release the gas it stalls and the battery light comes on. The batter guage is at half and it doesn't seem to be draining, so I don't think it's the alternator.

We have had a previoius problem where it was a "hard" start and had to turn it over a couple of times before it would start and stay running.

Hi wldathrt31, Welcome to 2carpros and TY for the donation

Lets start by cleaning out the idle air control valve, PCV and EGR valves, also clean the MAF sensor with an electronic cleaner CRC and test the throttle position sensor-let me know

My 1999 Ford Explorer acts as if it is going to die while idling. If the headlights, the radio, heater, or air conditioner are on, I have to fight to keep it running. Is this an alternator problem?

Actually, the alt sounds fine. It is under more load with everything on; thus, it puts more strain on the engine.

As far as the engine, has the check engine light ever come on? Have you checked for vacuum leaks?

Let me know.
Joe