Question about 2001 Hyundai Accent
Step on pedal no throttle pump actuation
This is an injected engine, carbs having gone the way of the horse and buggy, so it has no "throttle pump". I assume by that you meant accelerator pump, which on a carb engine would give an extra squirt of fueldown the carb, when the accelerator was moved, prreventing a hesitation on acceleration. Aside from one old Bosch system on an ancient Volvo, I'm unaware of any passenger car with any additional unit to provide supplemental fuel, except some older systems that employed a cold start valve, for cold enrichment. This being said,one of the duties of the throttle position sensor is to serve notice on the pcm, that there has been an increase in throttle opeming, so in essence, the tps serves as a sort of electronic version of an accelerator pump. You didn't mention codes, so this is where I would start looking. I'm assuming everything else is in reasonable shape. You will need a lab scope or some type of graphing meter, to visually "see" the signal from the tps during operational movement, and look for dropouts and glitches in the signal. Not everyone has access to this type of equipment, so it is possible at some shops, to have the problem diagnosed, for a fee, and then you can perform the repair yourself. Just be sure to let the hard working fellas in the garage know that this is your intent up front, as they will be losing income on repair labor and parts markup, and may have to adjust their fees accordingly. A good wrench that has good diagnostic skills is worth his weight in platinum, and keeping him happy can save you much wasted time, money, and effort. Feel free to get back to me if this does not address your problem directly, and we'll see what we can figure out from there. Thanks, and best of luck!
Posted on Feb 11, 2012
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Aug 19, 2017 | Cars & Trucks
The accelerator pedal
The accelerator pedal position (APP) sensor 1
The APP sensor 2
The throttle body assembly includes the following components:
The throttle position (TP) sensor 1
The TP sensor 2
The throttle actuator motor
The throttle plate
The engine control module (ECM)
The ECM monitors the driver demand for acceleration with 2 APP sensors. The APP sensor 1 signal voltage range is from about 0.98-4.16 volts as the accelerator pedal is moved from the rest pedal position to the full pedal travel position. The APP sensor 2 range is from about 0.49-2.08 volts as the accelerator pedal is moved from the rest pedal position to the full pedal travel position. The ECM processes this information along with other sensor inputs to command the throttle plate to a certain position.
The throttle plate is controlled with a direct current motor called a throttle actuator control motor. The ECM can move this motor in the forward or reverse direction by controlling battery voltage and/or ground to 2 internal drivers. The throttle plate is held at a 7 percent rest position using a constant force return spring. This spring holds the throttle plate to the rest position when there is no current flowing to the actuator motor.
The ECM monitors the throttle plate angle with 2 TP sensors. The TP sensor 1 signal voltage range is from about 0.5-4.25 volts as the throttle plate is moved from 0 percent to wide open throttle (WOT). The TP sensor 2 voltage range is from about 4.45-0.7 volts as the throttle plate is moved from 0 percent to WOT.
The ECM performs diagnostics that monitor the voltage levels of both APP sensors, both TP sensors, and the throttle actuator control motor circuit. It also monitors the spring return rate of both return springs that are housed internal to the throttle body assembly. These diagnostics are performed at different times based on whether the engine is running, not running, or whether the ECM is currently in a throttle body relearn procedure.
Every ignition cycle, the ECM performs a quick throttle return spring test to make sure the throttle plate can return to the 7 percent rest position from the 0 percent position. This is to ensure that the throttle plate can be brought to the rest position in case of an actuator motor circuit failure. Observe, under cold conditions, the ECM commands the throttle plate to 7 percent with the ignition ON and the engine OFF to release any ice that may have formed on the throttle plate.
Aug 21, 2016 | Cars & Trucks
Limited throttle mode--The ECM will continue to use the accelerator pedal for throttle control, however, the maximum throttle opening is limited.
Throttle default mode--The ECM will turn OFF the throttle actuator motor and the throttle will return to the spring loaded default position.
Forced idle mode--The ECM will perform the following actions:
Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned OFF
Ignore the accelerator pedal input
Engine shutdown mode--The ECM will disable fuel and de-energize the throttle actuator.
Did you have it checked for DTC's - diagnostic trouble code's related to the reduced engine power ?
All so has APP sensor gas pedal !
Accelerator Pedal Position (APP) Sensor
The accelerator pedal contains 2 individual accelerator pedal position (APP) sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with 3 circuits:
A 5-volt reference circuit
A low reference circuit
A signal circuit
The APP sensors are used to determine the pedal angle. The engine control module (ECM) provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors provide the ECM with signal voltage proportional to the pedal movement. The APP sensor 1 signal voltage at rest position is less than 1 volt and increases to more than 4 volts as the pedal is actuated. The APP sensor 2 signal voltage at rest position is less than 0.6 volt and increases to more than 2 volts as the pedal is actuated.
Your best bet is take your vehicle to the dealer !
May 03, 2016 | Cars & Trucks
Jun 10, 2015 | 2002 Chevrolet Tahoe
Limited throttle mode--The control module will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
Throttle default mode--The control module will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
Forced idle mode--The control module will perform the following actions:
Limit engine speed to idle by positioning throttle position, or by controlling fuel and spark if throttle is turned off.
Ignore accelerator pedal input.
Engine shutdown mode--The control module will disable fuel and de-energize the throttle actuator.
You need to have it checked for DTC'S - diagnostic trouble codes , probably a accelerator pedal position (APP) sensor or TPS - throttle position sensor !
Jun 01, 2015 | 2003 GMC Yukon Denali
Jan 27, 2014 | 2006 Chevrolet Aveo
May 25, 2017 | 2006 GMC Canyon
Aug 15, 2011 | Chevrolet TrailBlazer Cars & Trucks
Apr 15, 2011 | Ford F-150 Cars & Trucks
Jul 15, 2017 | 2003 GMC Yukon
207 people viewed this question
Usually answered in minutes!