Throttle response

ANSWER : Hello – the first task is to check for problem codes, whether the Check Engine light is on or not. I suspect there are still wiring issues with the throttle body, and if so, there should be problem codes to guide you. I recommend a engine inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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.

ANSWER : Without having the specifics on the vehicle and engine type, I can only give you a general direction to take. You may have an EGR system fault. EGR – Exhaust Gas Recirculation –
is designed to prevent knock, ping, and misfire under light throttle loads to help keep the combustion chambers cool. Since the exhaust gases have already been burned, they are cooler than the combustion chamber during ignition.

This prevents pre-ignition misfiring and it does not function at full throttle. A stuck/ inoperative EGR valve can contribute to the problem. Also, if any EGR tubes or passages are clogged with carbon due to age and mileage, the EGR "loop" will not function. I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine if the EGR valve needs to be replaced.

ANSWER : The engine running rough for a moment after using throttle body cleaner is a normal symptom. This should only last for a short period of time and then go away. If the issue does not go away after a few start ups or a short drive, it is possible that the throttle position sensor or mass air flow sensor could have been damaged as a result of using the throttle body cleaner. Many throttle body cleaners will specify if they are sensor safe. IF the throttle body cleaner is not sensor safe, one of the sensors may be fouled out. I would recommend having a drivability inspection performed on your vehicle to determine the exact cause if this issue persists. Consider YourMechanic, as a certified technician can come to your home or office to determine the cause of this issue.

ANSWER : Hello. The meter setting will depend on what BBK requires you to set the throttle body at. If the setting is voltage related then you need to set your meter to DC volts. That is usually what they recommend. If it is a resistance reading that they need you will set it to Ohm’s. If this is something that you would prefer to have done, consider YourMechanic, as a certified mechanic can come to your home to adjust this and insure a proper replacement of your throttle body.

ANSWER : It sounds like you are describing the symptoms of a failing throttle position sensor. The throttle position sensor monitors the throttle position of the throttle plate inside the throttle body in relation to your foot position on the gas pedal. Based upon the inputs from the sensor reading your foot’s position on the pedal, the ECU then makes the direction to supply more or less fuel to the motor. When this sensor is not working properly, this can cause intermittent responses when pressing the gas pedal.

There are trouble codes that are typically associated with the TPS. One code will set if the TPS voltage is too high when the computer expects to see it lower. Another code will set if the TPS voltage is lower than the computer expects to see. The TPS code for low voltage is the most common and will usually set if the TPS is out of adjustment or the sensor has failed. The first thing you should do when you get a TPS code is to check adjustment and signal output of the TP sensor before replacing it. Be sure to wiggle all connections while watching scan data/voltage readout to make sure the problem is not a loose or bad connection.

There are circumstances that could occur with a failing throttle position sensor that may not set a trouble code. One of the most common symptoms of a failing TPS would be a tip-in hesitation or stumble when you apply throttle to take off from a stop. This can be caused by a dead spot in the TP sensor’s internal circuitry, which usually causes the output voltage signal to not change (or it drops out) when the throttle opens. Unfortunately this type of failure is not easy to diagnose without the proper tool – a digital waveform scope. Most digital volt meters and scan tool displays will not respond fast enough to show this type of a glitch; but some may. If you do find this fault, then the obvious fix is to replace the TP sensor. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

ANSWER : If the engine is equipped with a throttle body injection system, then you should disconnect both injector harnesses and then turn the engine on to see if it looks like the injectors are putting fuel into the engine or the engine will still start and run like it did before. If it is, then your pressure regulator is leaking on the throttle body if you do not see the fuel injectors leaking fuel. The injector seal o-rings should be replaced if you see fuel coming from the injectors with them disconnected. The most common cause is the fuel pressure regulator diaphragm leaking fuel and needing replacement. If you want to have this looked at, a certified technician from YourMechanic can come to your car’s location to diagnose your car’s starting issue and let you know what repairs to proceed with.

ANSWER : Hi there. Check the resistance on the throttle position sensor on the throttle body and the throttle pedal position sensor on the gas pedal. There should be a resistance on the sensors. If one or both sensors have no resistance or have a really high resistance, then I recommend replacing that or both sensors. If you need further assistance with your throttle body service message, then seek out a professional, such as one from Your Mechanic, to help you.