adjust the throttle position sensor

1 = mixture screw 

2 = ISC 

3 = TPS 

4 = ISC Servo harness 

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Here is the adjustment procedure: 

"Idle Speed Control and throttle position sensor adjustment for 1.8 turbo engine. 

This adjustment is very important. Driveability depends mainly on this adjustment.

When the ISC servo, throttle positionsensor, mixing body or throttle body has been removed

or replaced, be sure to make adjustment by the following procedure. 

1- Run the cold engine at fast idle until the coolant temperature is raised to 85* to 90* C

(185* to 215* F). 

2- Stop the engine 

3- Disconnect the accelerator cable from the throttle lever of the injection mixer. 

4- Loosen (but do not remove) the 2 screws securing the throttle position sensor and

turn the sensor fully clockwise (around 30° of rotation) and then secure it again

with the screws. 

5- Turn the ignition switch to the "ON" position for more than 15 seconds, then

turn the switch to "OFF". This will set theISC servo to the specified position. 

6- Disconnect the ISC servo harness connector. 

7- Start the engine 

8- Check the engine speed and adjust to specification (~750rpm) with the adjusting screw

on the throttle. 

9- Stop the engine. 

10- In order to read the output voltage of the TPS, insert the digital voltmeter test probe

from the rubber cap side of theTPS connector and bring it into contact with the pins

on the connector. Insert the test probe leads into the output and theground. (There are 3

holes on the rubber cap side that you can insert the tester into. Insert the tester pins

into the 2 holes that give you the number closest to .50 V when you turn the ignition to

"ON". You'll know if you're doing it right or wrong because if you do it wrong you'll get a

ridiculously high number with the throttle isn't pressed. You should see a number close

to .50 V. If you see a high number like 2.22 V you're doing it wrong.) 

11- Move the ignition switch from "OFF" to the "ON" position. Do not start the engine. 

12- Read the throttle position sensor output voltage. 

13- If the measurement of the output voltage does not agree with .048 + or - 0.03 V (which

it obviously wont since you loosened it and turned it fully clockwise. I'm quoting the book

though), loosen the TPS mounting screws and turn it counterclockwise until the voltage is

0.48 + or - 0.03 V. (In other words, anything from .51 to .45 V is good). Then

tighten the screws after applying sealant. (Don't worry about the sealant. Be careful not to

overtighten the screws though because the sensor is plastic and it'll definitely break if you

tighen it too hard.) 

14- Fully open the throttle valve once, the let it return to it's original position and

check the voltage again. Make adjustment if necessary. 

15- Remove the voltmeter (from the TPS wiring harness connector) and reconnect the ISC

servo harness connector. 

16- Make sure that the curb idle speed is normal and then stop the engine. 

17- Turn the ignition swtich from OFF to ON and after 15 seconds return it to OFF. 

18- Connect the accelerator cable to the throttle lever of the injection mixer

and adjust the accelerator cable (Leave some slack in the cable, over tightening will raise

your idle and cause problems).