Planning the next
AO Silver Member
Join Date: May 2007
Location: United Kingdom
I've had a look at the workshop manual. You may be able to actually test the sensor in-situ if you have a multimeter.
1) Disconnect the in-line connector by the plenum.
The connectors should have numbers etched into them adjacent to the 3 pins.
Pin 3 is ground ( you can check this with a continuity test to the car body )
Pin 1 joins the throttle sensor and then goes on to the car's ECU. This is a stabilised 5 volt supply. With the ignition on, check for 5v on pin 1.
pin 2 is the sensor output back to the car's ecu. The sensor works on a metal ridge on the exhaust cam with a gap in it. As the cam rotates the gap will pass through the sensor and according to the manual, when this happens, the voltage will drop sharply.
So, to test the sensor, albeit in a crude way :
Check pins 1 and 3 as above. One should have 5v and the other connected to ground. If not, investigate the problem.
Remove the right front roadwheel and the plastic cam belt cover so you can see the metal ridge on the exhaust pulley.
Apply 5v to pin 1 of the sensor and ground pin 3.
Measure the voltage on pin 2.
Put the car in 5th, and rotate the brake disk to turn over the engine ( it'll help to remove the spark plugs to do this ). When the gap in the metal ridge passes through the sensor, the voltage on pin 2 should drop and increase again after the gap has passed through.
A better test if you should have or know someone with an oscilloscope would be to measure pin 2 with the engine running. You should see a nice drop in the signal each rotation.