Truck dies when not on the throttle.
Hi, I have a 1995, Ford F-150, extended cab, 2wd, 2 tank pickup with the 5.0 efi. When I am driving but step on the brakes to stop the engine dies unless I put it into neutral and step on the throttle. I have replaced the entire ignition system from plugs to ignition control. I've replaced the fuel regulator and filter. She runs like a dream going down the road with no hesitation or lack of power. Just at an idle she dies. At low throttle she backfires. I replaced the egr sensor also. I am at a complete loss. I'm gonna try timing again to see if that is it. Any help would be appreciate
Experienced mechanics share their insights in answering this question :
Hello.
A few things I would check are the timing, the idle air control valve, and the condition of the vacuum hoses. Retarded ignition timing can sometimes cause low throttle issues, and can definitely cause stalling. The idle air control valve is the component that is responsible for maintaining engine idle speed. If it fails or has an issue the engine will have trouble, or will not be able to hold a proper idle. Finally, vacuum leaks due to old or broken vacuum lines can also cause stalling and low rpm performance. I would verify the timing and then check the idle air control valve, and go from there. If you need help, a technician from YourMechanic can come to your home or office to inspect your car dying problem and replace the idle control valve if necessary.
Regards,
Eduardo
YourMechanic
How to Identify and Fix Common car Problems ?
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Common reasons for this to happen:
A defective TCS or torque converter solenoid can also cause this issue. Low fuel pressure, dirty or defective fuel injectors, or broken fuel pump: The fuel pump is responsible for transferring fuel from the tank to the engine.
The most common reasons a Ford F-150 engine stalling are the fuel system, the air intake system, or the ignition system.
A car dies while idling but restarts later due to misfiring ignition too. If the wires in the wiring harness are corroded or loose, the car will lose voltage because of the unstable connection to the ignition circuit. As a result, the engine won`t have adequate power to stay functioning when the speed slows down.
The most common cause of engine sputtering are issues with the fuel system. These can range from bad fuel filters, fuel pump issues, or fuel injector issues. The other possible source of the problem would be due to poor ignition – think spark plugs or ignition coil problems.
Running out of fuel is one of the most common causes of engine stalling, but dirty fuel injectors or a plugged fuel filter can also be the culprit. Your engine needs air to run properly as well. This air is received through the air intake, which also helps clean the air before it gets to the engine.
Specially tuned for truck customers, Auto Start-Stop shuts off the engine when the vehicle is at a stop – except when towing or in four-wheel-drive mode – to give drivers power on demand when they need it most. When the brake is released, the engine restarts quickly.
If your powertrain control computer is misreading idle speeds, this can cause a high idling malfunction. When your car`s throttle is malfunctioning, this can cause your car to stall or idle high. Often this is a result of dirt buildup in the air intake. Other times it can be a problem with a cracked intake tube.
The main cause of engine stall at high temperature is rapid fuel boiling by increasing fuel temperature. This causes a lot of vapor. Such vapor flows into the fuel pump which leading to decrease the pump load and the current consumption of the fuel pump continuously. This ultimately results in engine stall.
When your engine shuts off when you slow the car down its often as a result of a: Malfunctioning transmission. Low fuel pressure, dirty or defective fuel injectors, or broken fuel pump. Bad oxygen sensor or mass flow sensor.
It might be backfiring or it just sounds and feels like it is not working at normal power. A sputtering engine means that it is not achieving full combustion. It could be the sign of a very simple problem or it could be a symptom of a much more concerning engine, fuel system or exhaust system issue.
A clogged fuel or air filter can make your engine sputter and your acceleration lag because the engine is not getting enough fuel or air, respectively. The combustion chamber needs the correct amount of air and fuel in order to generate combustion efficiently.
With current models the only way to perform an idle shutdown bypass is to engage cruise control, which should be located on the steering wheel. Hold down the button to raise vehicle RPM and release after 5 seconds or so. Right after, hit the gas pedal to keep the truck running in idle.
Your vehicle may be equipped with an engine idle shutdown system. This system automatically shuts down your engine when it has been idling in P (Park) or N (Neutral) for five minutes (parking brake set) or 15 minutes (parking brake not set).
If the vehicle randomly shuts off while driving or stationary, there is usually an issue with the engine. Typical patterns here are issues with the ignition system, mixture preparation or fuel. A known error here is that the vehicle was refueled with the wrong type of fuel.
Worn or Fouled Spark Plugs
Ignition misfire can make your engine stall at idle.
A rough idling engine can be caused by spark plugs or spark plug wires. Spark plugs use the electrical current received from ignition coils to ignite the air/fuel mixture within the combustion chamber. A plug that is damaged or installed incorrectly can result in fuel being burned at an inconsistent rate.
The signal from the coolant temperature sensor tells the engine`s computer when to apply extra gasoline during a cold start. A faulty sensor can confuse the computer, keeping it from providing enough fuel. As a result, the engine may hesitate or stall.
Simply put, a rough idle describes an engine that is not firing consistently when your vehicle is in park, with no gas applied. Most vehicles idle between 600 and 1,200 RPM and should hold their idle speed.
An idle air control valve, also called an idle air sensor control motor, is an electrically operated valve that controls the amount of air that bypasses the throttle plate in cars with a fuel injection system [source: Autozone]. This causes the idling speed of the engine to change as needed.
To check whether the idle air control valve is functioning properly, start the engine and let it run for about 10 to 15 minutes. If the valve is functioning correctly, the engine will sound good and the idle will be steady versus too high, too low, or inconsistent.
A mixture of air and fuel that`s got too much gas in it is called, “rich.” When a rix air/fuel mixture is ignited in the cylinder, the whole mixture won`t be burned up by the time the exhaust valves open. Then, the combustion process will flow to the exhaust where a backfire will take place.
Another possible cause of your backfire is a spark plug refusing to “spark” when the exhaust valve opens. If the air/fuel mixture has become too rich, unburned fuel is left in the exhaust system. The misfired spark plug ignites the rich air/fuel mixture, causing a loud “bang” in the tail pipe.
On the other end of the spectrum, a bad fuel pump, vacuum leak, or clogged fuel injectors could cause an air-fuel ratio that`s too lean; that is, it has too much air and not enough fuel. Though this is the opposite problem, it can also cause a backfire as vapor escapes into the exhaust and combusts there.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
I changed fuel pump and truck ran great for 3 days. Now after 3 days truck dies. It will start runs few min then dies like before
ANSWER : Check the bottom of the fuel tank for sediment. Age and mileage could have accumulated a lot of it at the bottom of the tank. If you did not, check and change the fuel filter. Rule of thumb – replace the fuel filter any time you replace a fuel pump. Also, check the wiring for any chaffing on the fuel pump when you remove it. While your problem is kind of unique, I have seen many GM truck fuel tank baffle loosen over time, occasionally rubbing against the fuel pump can intermittently short it out and/or block the fuel pump pick up. To have this diagnosed, consider having a certified expert from YourMechanic inspect the stalling issue to have this corrected.
Read Full Q/A … : Truck dies when not on the throttle.
My truck died while driving. Now will start, but dies when I push brake. If I start in neutral, I can put in drive and go but dies – 2003 Ford F250
ANSWER : Hello – your symptoms suggest that once your cold start features are no longer needed – engine warming up – there is an air "leak" that ruins low speed running. Causes could be a leaking exhaust gas recirculation (EGR) valve, or leak in the air intake. A failing fuel pump relay (burned contacts) could cause similar behavior, contacts become hot, then won’t pass enough current to run the pump. Failing pump can also act this way – gets hot and fails. I recommend a starts, then dies inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.
Read Full Q/A … : Truck dies when not on the throttle.
I parked my truck for 5-10 mins. Tried to turn it on, now it wont start, called a tow tow truck 15-20mins later my truck turned on
ANSWER : It is very likely that you have a powertrain control module failure. This can happen often on many GM vehicles. I would recommend having the powertrain control module tested and replaced as necessary in order to resolve this issue. After the powertrain control module is replaced, a reflash procedure will be required so that the vehicle can relearn all of its primary engine data. Once the reflash is completed, your vehicle should no longer have this issue.
Read Full Q/A … : Truck dies when not on the throttle.
I changed the fuel pump and truck ran great for 3 days. Now after 3 days, the truck dies. It will start running for a few minutes, then dies like before.
ANSWER : Hi there, thanks for writing in. I’d be happy to help. It sounds like you should disconnect the connector to the fuel pump and inspect it for any signs of getting hot. The female connections may be too loose on the fuel pump and lose contact after running and getting hot. If there are indeed any signs of problems, then I’d suggest replacing connector and adding dielectric lube to pins before installation. This should solve the problem, but if you continue to experience issues, feel free to reach out to us for help again.
Read Full Q/A … : Truck dies when not on the throttle.
I have to manually open the throttle plate to start my truck. What causes the throttle plate to stay closed?
ANSWER : This suggests you may have a bad throttle control actuator. This is a module near the intake that operates the opening and closing of the throttle plate. This works in conjunction with the throttle position sensor which monitors your gas pedal position. When the electronic throttle control actuator is not working properly, this will cause the type of problem you have where the throttle plate will not move according to the inputs from the throttle position sensor.
I would recommend having an expert, such as one from YourMechanic, come to your home to determine why your car is starting and then dying in the way you have described, and what problems there may be with the throttle.
Read Full Q/A … : Truck dies when not on the throttle.
Truck won’t stay running
ANSWER : Hey there. Did you charge the battery before starting the truck with the new alternator? An alternator trying to maintain system charge and charge the battery from dead puts a lot of stress on the alternator and can cause a premature failure. If the truck will only run while you give it throttle, you may have a clogged or malfunctioning idle air control valve. It may be time to replace that battery as well as have the engine control systems checked to see why the truck won’t run without adding throttle. For a problem like this, consider YourMechanic, as a certified technician from YourMechanic can come to your car’s location to address your car problems.
Read Full Q/A … : Truck dies when not on the throttle.
When the truck is rolling with clutch in the truck will idle rough and sometimes dies.
ANSWER : This is a common symptom of the idle air control valve failing. This unit monitors the air intake as it is mixed with fuel prior to entering the motor. When this fails, this will cause a rough idle at low RPM’s. I would recommend having an expert from YourMechanic come to your home to diagnose the rough idle firsthand for an accurate repair.
Read Full Q/A … : Truck dies when not on the throttle.
I had my truck towed on a flat bed tow truck and now it is vibrating really bad and it sounds like my tires are howling
ANSWER : The problem sounds like you have flat spots on the tires in the rear when the tow truck operator dragged and pushed the truck with the transmission locked. I would recommend having a vehicle safety inspection to see if there is tire damage or other possible damage done by the tow truck. Have a mechanic from YourMechanic come and do the inspection and check the problems for you.
Read Full Q/A … : Truck dies when not on the throttle.
