Jump to content

Throttle Position Sensor


Guest deebee 55

Recommended Posts

Guest deebee 55

Hi i have a rover 2.0 t series super spec which starts and runs on tick over but give it the slightest bit of throttle and it cuts out ,.

 

ive been in-touch with with Alan richey who has made a study of the ecu and he told me it sounded like the TPS , i checked this out and he seems to have put his finger on the problem because with or without it plugged up its just the same i need to discover if its the wiring or the sensor does anyone know how to test the sensor before i go shelling out my had earnt , thanks

 

Dave

Link to comment
Share on other sites

To hook up your throttle position sensor (TPS), disconnect the TPS, and use a digital multi-meter. Switch it to measure resistance. The resistance between two of the connections will stay the same when the throttle is moved. Find those two - one will be the +5 Vref and the other a ground. The third is the sense wire to the MegaSquirt® controller. To figure out which wire is the +5 Vref and which is the ground, connect your meter to one of those two connections and the other to the TPS sense connection.

If you read a high resistance which gets lower as you open the throttle, then disconnected wire is the one which goes to ground, the other one which had the continuous resistance goes to the +5 Vref from the MegaSquirt® EFI Controller, and the remaining wire is the TPS sense wire.

 

 

 

 

 

 

 

 

courtesy of steve in stockport

Edited by tractor
Link to comment
Share on other sites

Dave, the 3 wires to the Rover TPS should be:

yellow/green - sensor wipe to ECU pin 8

yellow/purple - +5v supply from ECU pin 9

pink/black - earth return to ECU pin 30

 

(although my notes are confused and 8&9 could be the other way round)

 

Andy

Link to comment
Share on other sites

Guest deebee 55

Hi guys thanks for the replys

i have the sensor plug with the correct wires in , the reason i was suspecting the wiring was the car has been sat for a great length of time and the weight of the rest of the loom has caused a kink in the cables as it leaves the plug and as for all tence and purpose the sensor is new (not used ever in twelve years ) i wondered if there was a test for the sensor so if it proved the sensor was ok i could look more closely at the cables Eh does this make sense

 

Dave

Link to comment
Share on other sites

Dave,

When I thought I had a TP Sensor problem on my SuperSpec, I received this info from a chap on the Rover forums...

 

There are 3 pins/connectors on the TPS. The outer 2 give a fixed resistance and the middle one is the wiper. With the pedal not depressed and ignition off (stepper motor not energised), you'll get a low resistance between the wiper and one of the 2 outer pins, and then as you depress the pedal the resistance should increase smoothly towards that across the outer 2 pins.

TPS outer pins 5.5kOhm.
wiper (middle) pin to top pin at idle (~0.6kOhm).

 

With ignition on you should get 5v on pin 1 of the TPS - yellow/purple from ECU pin 9

3rd pin should be pink/black to earth through the ECU pin 30

middle pin of the TPS should be the wiper giving variable voltage over yellow/green back to the ECU pin 8

 

To check cable continuity between the sensor and the ECU you will need to find those wires in the 36 pin ECU connector and test back to the sensor plug. The connector has seals in it so it is difficult to backprobe. I used a needle carefully pushed through the outer wire covering.

 

I would also add that I had a dodgy plug on my TPS sensor. It kept coming loose or falling off as the metal U spring clip was missing. Made myself a new clip to hold it in properly. Also cleaned up all the contacts with switch cleaner spray as it is prone to suffer from poor contacts.

 

Cheers, Andy

Link to comment
Share on other sites

Guest deebee 55

thanks for taking time to respond after doing the suggested checks i think the problem was the ecu was just sorting its self out and will get better with time

Cheers

Dave

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...