Throttle position senso

[markt944]

Has anybody tested theres useing the info on the clarks garage website no matter what i do it doesnt give the results like they say

I dont really know what im doing with my meter ,but its on the 20k range


if i test terminal 2/18 idle speed contact i get 000 when throttle closed, 1 when its open {i think thats my meter it should be 0}

term 3 /18 wide open contact i get 000 when full open 1 in all other positions

That totally different to what the website says

I have a horrible hesitation at low rpm at slow speeds{right were the idle contact is being switched on /off} and am trying to test things before i buy

Thanks in advance for any help

[bazar01]

TPS is just two switch contacts inside the plastic casing.

Set your meter to lowest resitance scale, not 20k.
Throttle closed, idle switch should be closed and read 0.0-0.1ohms, WOT open at Megaohms (very high resistance)
Throttle partially open, both switches open at Megaohms.
Throttle full open, WOT should be closed at 0.0-0.1 ohms.

[markt944]

Ok thanks i managed to get the cover off the switch and did notice that its only 2 switches , but i also noticed that theres a little capacitor across the WOT contact

Do u know whats this is for ,also my multi meter shows 1 on the scale when u turn it on and over to ohms{leads not touching is this right}

Mark

[bazar01]

Originally Posted by markt944

Ok thanks i managed to get the cover off the switch and did notice that its only 2 switches , but i also noticed that theres a little capacitor across the WOT contact

Do u know whats this is for ,also my multi meter shows 1 on the scale when u turn it on and over to ohms{leads not touching is this right}

Mark

That's the highest resistance your digital meter can probably display at that scale (kOhms or MegOhms). If you can get a better one, you will appreciate it when troubleshooting electrical stuffs.

I did not notice a small capacitor across WOT just a microswitch for idle and a set of exposed copper leads and contacts for WOT. Do you have pic? Probably a suppressor to prevent noise or arcing but I doubt it?

[bazar01]

Found a pic but can't see the capacitor you mentioned.
Have you done a tune up to address the hesitation?

[bearone2]

Originally Posted by markt944

Has anybody tested theres useing the info on the clarks garage website no matter what i do it doesnt give the results like they say

I dont really know what im doing with my meter ,but its on the 20k range


if i test terminal 2/18 idle speed contact i get 000 when throttle closed, 1 when its open {i think thats my meter it should be 0}

term 3 /18 wide open contact i get 000 when full open 1 in all other positions

That totally different to what the website says

I have a horrible hesitation at low rpm at slow speeds{right were the idle contact is being switched on /off} and am trying to test things before i buy

Thanks in advance for any help

i use autoranging for all measurements and use an older fluke dvm.

2/18 with throttle closed should be "0", 3/18 "000" throttle open.

as you open the throttle linkage you should hear a click, that's where it goes to "000"/infinity if it's adjusted properly.

put a screwdriver in the back of the pictured tps, opening the swith like the throttle and notice how the fingers start to move.

where the fingers ride, carbon tracking will ocur and could be your hesitation.
i used to clean them on an older bosch fi system in a volvo with an eraser/burnishing, sharpened like a pencil to remove the carbon by gently lifting up the fingers.

the tps tells the dme if you're idling/accelerating/decelerating.

[markt944]

Thanks for the pic mine the same as that the capacitor is across the wide open switch ,where its soldered to the connections bottom left

As for carbon track thats how i thought it would work ,suprised to find its just 2 switches
Infact they are so simple surly they very rarly give problems if ever adjustment being the main problem


I think when my cheap meter reads 1 thats infinity 000 is the resistance i got it the wrong way round {or at least i thnk i have} it is reading 000 because i have it set on to higer resistance reading on the dial

If i switch my meter on,and over to a resistance setting leads not touching each other or anythin else it shows 1




Thanks again Mark

[markt944]

Think iv finally found the problem i had with hesitation

Took the switch to bits the other day to test it also manage to get the cover off without doing to much damage to it

After finding out how to use my meter properly it was fully working ,so i taped the case back on and but it back on the car .It seemed a bit better but hesitation is intermitent anyway

Yesterday i took it off again to superglue the case back on permanently car seemed ok

On the way home tonight and the car was stalling at every junction got onto my driveway and it wouldnt tick over .Here we go its a cold dark night playing about with it

First thing i went back to throttle switch and adjusted it, and it started ticking over again,so i took it off to retest .This time nothing ! so i had to butcher the case this time to get into it after superglueing it yesterday !

A direct test of the actual switches and they worked ,but nothing at the connector idle or wide open contact

Anyway after some time scratchin my head i found the soldered contact on the wide open contact were cracked Bingo !

By the way the switch is designed these breaks were causing the idle contact not to work and be intermitent .Soldered them back up and it tested out as it should

Went out in the car and the hesitation seems to have stopped {touch wood}

Trouble is the case is now butchered so i will order a new one


Its funny because i started it up the other morning and it was only runnig on 3 cylinder for a minute or so till it cleared .like today it was freezing the cold must of opened up the cracks

So like i say touch wood and the problem is sorted

Mark