Yesterday I drove on the highway for 45 minutes and when I got off my truck stalled repeatedly.I parked and came back in an hours and the truck drove fine.
My car has 179899 miles.
My car has a manual transmission.
Hi There, There are many things that may cause the truck to stall both at speed or at an idle as you describe. If the truck stalls at an idle, this may be related to something called an idle air control valve. The idle air control valve is a small valve on the engine’s intake system that reads the air intake as it comes into the motor. This is controlled by the car’s ECM which uses this information to make adjustments to the air/fuel ratio depending on various inputs such as outside air temperature, intake air temperature, load and various other things. As you accelerate, your car’s engine is receiving a much higher dose of fuel than when at idle and conversely, when you let off the gas pedal, there is a sudden change in this fuel supply as a result of your foot letting off the pedal. When this happens, the job of the idle air control valve is to bring this deceleration down to a slow and smooth idle rather than suddenly cutting off the fuel supply causing the motor to die. When the idle air control valve is not working properly, this cause a disruption in this process resulting in the engine not being able to idle properly.
The intermittent running condition as you describe, sounds like a potentially failing ignition coil. This is a common symptom of a heat cycling effect that happens when an ignition coil begins to fail. Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeatedly The insulation develops small fractures that open when heated and close when cooled. When open, they allow shorting of coil windings and decrease or eliminate the coil’s ability to function. This type of temperature cycling happens because every time you shut the engine off, the fan stops running, the coolant stops flowing and the temperature under the hood rises. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle.
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