Pedal and Throttle Test

This step is will allow you to test the Pedal and Throttle TPS operation. It also determines the maximum power allowed on the throttle motor. Most throttles have plastic gears and will be damaged if too much power is applied to them. The butterfly may also hit the barrel too hard causing damage that can lead to a sticky throttle body. The throttle TPS calibration are done automatically by the TxW which means you do not have to open it up to see if it is working correctly.

NB! Do not attempt to calibrate the TPS before this procedure is done.

First set the following values before proceeding:

Under the Sensors tab, use the fuel pressure block to set the maximum power allowed to the motor in duty cycle PWM. On the Fuel Pump High, set a safe value of 128 which is 50% power. A value of 254 = 100% Power. This value may be changed later in the program to less or higher values.

Now go to the fuel pages and set the ACC values to Zero. This represents opening and closing PWM or Duty Signals and then Gain or Proportional settings.  

Now go to the Sensors page and set the Check the Crank Test signal to On. This will deactivate throttle control and calibration, and will display the actual values of the Pedal TPS and the Throttle TPS on the real-time bars. The Throttle TPS is displayed on the POT bar and the Pedal TPS is displayed on the TPS bar. On simulators it may use different potentiometers as we use different inputs on the TxW.

NB! Disconnect your engine ECU outputs as this setup requires the pedal to be moved plenty of times which will activate the prime function and inject petrol into the intake manifold.

To test the Pedal TPS look at the real time display and press the pedal fully and then release it again. The TPS bar should move a fair distance in the display but should not reach maximum or minimum limit. If it does, then use the other signal on the Pedal TPS, or adjust the sensor inside so that it has free play. See min and max example below.

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Also note if the action is inverted. This will help setup the pedal logic on rising- or falling edge later during calibration. The standard setup is rising volts with throttle depression. It may be an incorrect connection of the 5 volt and ground wires which may be swopped around.  Below is the calibration tab when it is opened to indicate rising edge.

To test the throttle TPS for correct operation you need to manually press the throttle open and close. This must be done by finger or soft plastic so that you don’t damage the butterfly or tube. First press it close, then leave it at rest point, then open it fully. The POT bar should move a fair distance in the display but should not reach maximum or minimum limit. If it does, then use the other signal on the throttle TPS or adjust the sensor inside so that it has free play. You should see some results like below:

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Also note if the action is inverted. It must be rising in value with increase of throttle. If it is falling volts with opening, then it may be incorrect connection of the 5 volt and ground wires.

Note. If you can’t get to the throttle to test the TPS then you can skip to the next step and open it from the TxW side and see if it functions correct. You will only be able to see the rest and open position.

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Determine Maximum Duty cycle.

Make sure Test is on.   Now adjust the Opening Duty with the arrow and increase it gradually till the throttle opens.

Look carefully at the throttle TPS on the POT bar. Adjust it ill it reaches the maximum determined in the previous test which was 71%. If you could not do the previous test, then adjust it till you don’t see any more increase in throttle movement on the POT bar. Adjust it lower again till you can see throttle movement so that you don’t have too much power on it. Then slightly up so that you can assure maximum openening.

Now put the Test off.  If you put Test back on, then the throttle will open again. It may be slow to react as it gets just enough power to its motor. Now increase the Opening Duty more and testing throttle response every time you alternate the Test function. Do this till the throttle responds just fast enough without making the value more than is needed. You should hear it reaching its full open limit but not too hard. If you make the duty more, then you may risk damaging the plastic gears. If it is too slow then it may respond sluggish in blip conditions. If this value increase more than 128 then you may need to increase the Fuel Pump High value.

Now take this Opening Duty value and type it in the High Limit Duty Cycle block. This will prevent the TxW to ever exceed this amount of power to the unit.

Now put the Test function off and proceed with the next Step.