Pops and idles rough, stalls out

ANSWER : Hello. I would start by scanning the vehicle for codes and checking to see if all of the sensors are reading correctly. If everything looks good then chances are it needs a new computer. I have seen the computers fail on these vehicles over and over again causing the ignition circuits to not work correctly which causes the vehicle to run just like this. If you need to have this looked at, consider YourMechanic, as a certified mechanic can come to you to [diagnose why the vehicle is running like this] https://www.yourmechanic.com/services/car-idle-is-rough-inspection

ANSWER : A number of components or faults can cause your issues. A vacuum leak can cause your issues. Depending on the vehicle, components such as the mass airflow sensor, throttle position sensor, coolant temperature sensor, and a number of others can be the cause. Since randomly replacing parts can get expensive as most electronic components are not returnable once installed, having a certified technician, such as one from YourMechanic, diagnose the stalling/surging is the best place to start.

ANSWER : Hello. This is a common problem with the variable valve timing solenoid on this engine. I have changed quite a few of these due to failure. I always start by checking the codes and testing the solenoids and the connectors as some of the time the connectors fail and have poor connections. There have been a few times that I have seen these codes due to low oil or the wrong oil and from the camshaft actuators failing, but most of the time it is due to the solenoids. If you are planning on having this fixed, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair the rough idling issue for you.

ANSWER : Hello, thank you for writing in. The vehicle is struggling to keep up with all of the different accessories when the engine is idling. This is typically due to an issue with the air intake, fuel intake, or the sensors that monitor and control them. Start by having the vehicle scanned for codes at your local automotive parts store, or by a different technician. If no codes are present, attempt to clean the throttle body, idle air control valve, and the throttle position sensor. If there are codes present, then you can use them to point you to the issue at hand, and take corrective action from there. For more help with diagnostics or resolving the issue, contact our service department to schedule an appointment.

ANSWER : Hi there. The fact you able to get the idle speed to drop by tapping the gas pedal, lead me to believe the high idle is due to a sticking accelerator cable. Another possibility could be, a faulty throttle body not allowing the throttle to return to the closed position. Proper diagnoses should be performed to avoid unnecessary repairs. I recommend having your vehicles high idle be diagnosed and repaired by a certified technician, such as one from YourMechanic.

ANSWER : Failures in the charging circuit (alternator, etc.) do not typically cause a rough idle. A faulty throttle position sensor and/or clogged fuel injectors can cause the engine to run roughly but those are just two among many, many potential causes of a rough running engine. What will help you is a rough idle diagnostic during which the individual cylinder firing patterns can be evaluated on a scope. Those firing patterns will allow the mechanic to see if perhaps there is "a" or a couple bad cylinders and also whether the engine is experiencing a fuel system versus ignition system problem and in which cylinders. On an engine with so many miles, 240,000 in your case, compression should be tested in each cylinder as wear in the engine could potentially cause enough imbalance, from cylinder to cylinder, to cause the engine to run roughly. You have to keep in mind that typically there will be multiple issues with an old engine, for example you could have dirty fuel injectors, a sticky EGR valve and fouled plugs due to the inevitable leakage from old valve stem oil seals, or any of a number of other combinations. The best thing to do, to see if you can get additional service life out of the engine, and you likely can, is to methodically and carefully go through the list of possibilities. YourMechanic certified technicians specialize in just that so if you set up a diagnostic, a technician will get to the bottom of this for you and give you repair options so that the engine can be restored to reasonable operating condition.

ANSWER : Hi there. Though this can be caused by a few different things most of the time it is caused by a failing throttle body. The throttle body will have a failure in the actuator motor and this occurs, most of the time without a code. I usually monitor the sensor readings of the throttle body and the accelerator pedal to see if there are any data issues. If not then I will usually replace the throttle body. If you are looking to have this throttle issue fixed, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the idling issue.

ANSWER : This may be related to a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements, such as engine temperature, intake air temperature, and electrical system load or voltage.

When you accelerate, the engine RPM increases, and, as you let off the gas, the RPM slowly returns to the normal idling speed. This is all controlled by the idle air control valve. When the engine RPM drops below the normal range of 750-800 RPM, this may indicate a dirty or faulty idle air control valve.

I would recommend having an expert, such as one from YourMechanic, come to your location to determine why the car is running rough and replace your idle air control valve if needed.