Potentiometer Info

[BRUN]

ive got a brand new potentiometer here and ive just been playing with it, thought id post up the values it gives to give some insight into it

this is with it not connected to anything, not even on a throttle body, just on my desk loose with my multimeter attached

red + green 1.89kohm
yellow + green 4.46kohm
yellow + red 6.35kohm

it seems to me that it would need to be set up with it disconnected from the connector plug, but obviously still on the throttle body, and the car not running

as you twist it around the resistance when testing red + green goes up, when testing yellow + green the resistance doesnt change at all, and when testing yellow + red the resistance goes down

thought this might help with all the conflicting posts about this particular item

[BRUN]

be aware that the values i have posted are not setup values, simply the values it gives sat on my desk, not adjusted in any way, just as it comes in the box

[stan]

LOL

so it gives a resistence value for a given position??! :lol: god, i wish someone would have said this earlier :roll: :lol: :lol:

nah seriously, the way it works, is the ecu sends out a voltage to the sensor, and the resistnce is "monitored" (since the ecu detects the voltaghe drop incurred by the resistence of the potentiometer). since the resistence changes with throttle positon (as you have seen from your test, and as i said earlier), the ecu has a load reference for every increment of throttle angle. the ecu uses this load value to determine the required fuelling and ignitin advance.

so to set it up, you use base values for known positions i.e. WOT and idle.

with my Emerald ecu its simply done by activating a set-up mode for the throttle pot, whereby from the foot off position (idle) you put your foot flat to the floor, and the ecu stores the max/min resistence values which represent idle and WOT. far`easier!!

[Coops]

yeah but most of us have got shite seimens reno ecu's!! so it aint that simple!!! set mine up tho n it seems spot on using chris h's set up values! what brun says is spot on tho, best bet i'd say is put potentiometer onto body off the car, not plugged in, set the value for yellow/green (one that doesnt change atall) spot on and bolt it on tight, thats what i did n its okay ATM, will follow up after shes been for a blast on the road n settled again!!

[Coops]

oh ah, heres chris' set up values, i used resistance with engine off but voltage with it on may work n all!! :D


red - yellow 5.78kohms 4.65V
red - green 2.01kohms 0.28V
yellow - green 4.27kohms 4.96V

voltage values are on a running engine around 13.8 volts at battery.

Thats what i use and they always work nicely.

[FlamingMonkey]

Might check these values out at dinner, what would I be adjusting if the values were out, anyone got any pics please?

[BRUN]

slacken the screws off and twist it

coops the value for yellow + green doesnt change, whatever you do to it

and stan no need for sarcasm, i knew what it did anyway i just thought testing one off the throttle body and posting about it might help a few people understand it, i read most posts on here whether i think i know about something or not, if i can pick up any info then brilliant !

wish the Renault ECU's were as advanced lol

[FlamingMonkey]

slacken the screws off and twist it

hehe twist what, undo the 2 screws and twist the red doofer?

[BRUN]

yup the red doofer, you will only need to turn it very slightly

[Coops]

good point!!! either way my car is now idling at 1000rpm constant all the time, that a bit high?cud potentiometer adjustment bring it down a bit?or shud i stop fiddlin n just drive the damn thing?!

[VIPERONE]

1000 k is fine mate factory figs suggest +or -100k

[stan]

wasnt directed at u fella....just wish people would listen

[BRUN]

yea sorry if it looked that way, once id read all of your post i kinda understood where you were coming from