Does Anyone Have Experience of these devices
there are 4 wires ( abcd) all fed by the ECU.
On my instalation , a 1.8 16v xantia the plug is vertical
'a' being at the back and 'd' towards the rad. [all 4 wires appear to be grey.]
At times I have an excessive tickover 2000+ nothing to do with the buttefly so I have assumed the problem lay with the above.
I have NOW confirmed that it winds in both directions and that it can wind itself out compleatly.
I hope that I have retrieved everything, a spring, a sleeve and the plungercone with it's thread and double keyway,
clearly I need to apply a voltage across some of the terminals to wind the
plunger back in so that I can re-insert the devise back into it's houseing.
If anyone has been here before it will save me experimenting.
Many thanks in anticipation.
To save anyone asking I connected it to another car with everything installed (which surprisingly ran reasonably well) without it's own motor being connected.
Idle Stepper Motor
Moderator: RichardW
i belive the reason these devices fail is they get fouled up with carbon from the induction, the usual trick is give it a blast out with carb cleaner, even though it might not last long after doing this, it just prooves it is at fault, before you buy a new one, thats all being you get it back together,
these motors are very presision devices, and opperate with the very tinnyest and rapid movement in normal use,
i think some one on the CCC web forum has just bought a new one from the dealer at about £125 or so squid, cough cough spluter spluter,
if you do buy a new one firstly try a local motor factors, or go straight to these people
http://www.fpuk.co.uk/main/index.asp
i have found them very helpfull indeed
regards malcolm
these motors are very presision devices, and opperate with the very tinnyest and rapid movement in normal use,
i think some one on the CCC web forum has just bought a new one from the dealer at about £125 or so squid, cough cough spluter spluter,
if you do buy a new one firstly try a local motor factors, or go straight to these people
http://www.fpuk.co.uk/main/index.asp
i have found them very helpfull indeed
regards malcolm
To my experience these devices have a tiny springloaded switch on the plunger tip.
This switch is brought out on 2 wires.
The remaining 2 wires would be the DCmotor windings, which simply runs either way according to connected polarity, then moving the plunger pushing the throttle flap.
The steppermotor is simply an electrically adjustable bottom stop for the throttle, with a sensor switch that signals to the computer that the driver has released the acc pedal (as then the springloaded throttle flap pushes back on the steppérmotor plunger tip switch).
Using an ohm meter it should be rather simple to find the relevant wire functions on the steppermotor.
The motor windings would have a few ohms (10-50 -ish ohms) while the switch is a zero/high ohm.
If your steppermotor functions well on another engine, it seems you have either a mechanical problem with your throttle flap bottom position (commonly carbonised as pr Malcolms suggestion) or you have a wiring problem to the unit.
Despite the tiny precision part, the steppermotor is very reliable and usually a good clean/lube makes it work reliable again for the lifetime of the car.
This switch is brought out on 2 wires.
The remaining 2 wires would be the DCmotor windings, which simply runs either way according to connected polarity, then moving the plunger pushing the throttle flap.
The steppermotor is simply an electrically adjustable bottom stop for the throttle, with a sensor switch that signals to the computer that the driver has released the acc pedal (as then the springloaded throttle flap pushes back on the steppérmotor plunger tip switch).
Using an ohm meter it should be rather simple to find the relevant wire functions on the steppermotor.
The motor windings would have a few ohms (10-50 -ish ohms) while the switch is a zero/high ohm.
If your steppermotor functions well on another engine, it seems you have either a mechanical problem with your throttle flap bottom position (commonly carbonised as pr Malcolms suggestion) or you have a wiring problem to the unit.
Despite the tiny precision part, the steppermotor is very reliable and usually a good clean/lube makes it work reliable again for the lifetime of the car.
Anders (DK) - '90 BX16Image
I've never investigated these, but if it's really a stepper motor, you won't be able to drive it with DC across a pair of terminals.
Steppers function by having current applied to a number of coils in succession (the actual number varies), and require a special circuit (or microcontroller etc) to sequence the coils correctly.
Steppers function by having current applied to a number of coils in succession (the actual number varies), and require a special circuit (or microcontroller etc) to sequence the coils correctly.
subject
cough cough spluter spluter,
Thanks
It appears that it is the outer two connections that drive the motor
ie , A & D
6volts did not do anything and 12v will not draw it in
(It managed to spit things out OK and I do not think I have lost anything )
In fact I now have it stuck!!!! it do not want to either draw on in or spin out; I supose that this is because the rotor is unsuported
It is drawing about 200mA.
Rest assured I will not be parting with £125, there is no desperate rush.
It looks as though there is a joint in the houseing and there are 4 little pegs that probably hold things to-geather.
If anyone has access to a dead one prehaps they could break it up and see what is in there ? I will wait before I do further damage.
Thanks
It appears that it is the outer two connections that drive the motor
ie , A & D
6volts did not do anything and 12v will not draw it in
(It managed to spit things out OK and I do not think I have lost anything )
In fact I now have it stuck!!!! it do not want to either draw on in or spin out; I supose that this is because the rotor is unsuported
It is drawing about 200mA.
Rest assured I will not be parting with £125, there is no desperate rush.
It looks as though there is a joint in the houseing and there are 4 little pegs that probably hold things to-geather.
If anyone has access to a dead one prehaps they could break it up and see what is in there ? I will wait before I do further damage.
i certainly wouldnt pay £125 squid either, that is why i sent you that web site link, as i think i payed between £40 and £60ish squid for one i fitted to a customers 1.8 16V XANT last year or so,
also Anders
these stepper motors act as an auxilary air supply and dont opperate the trotle flap, i think they are used for cold startting, but when they fail they affect the normal running and make the rev's unstable
regards malcolm
also Anders
these stepper motors act as an auxilary air supply and dont opperate the trotle flap, i think they are used for cold startting, but when they fail they affect the normal running and make the rev's unstable
regards malcolm
I beg your pardon malcolm ?citronut wrote:i certainly wouldnt pay £125 squid either, that is why i sent you that web site link, as i think i payed between £40 and £60ish squid for one i fitted to a customers 1.8 16V XANT last year or so,
also Anders
these stepper motors act as an auxilary air supply and dont opperate the trotle flap, i think they are used for cold startting, but when they fail they affect the normal running and make the rev's unstable
regards malcolm
Is it a stepper motor -
or is it an auxillary air valve -
??? I dont see any problems here as the difference on the 2 units is VERY clear :
A stepper motor moves the throtteflap.
An auxillary air valve controls the volume of air shunting the throttle.
Its 2 different worlds on how to control the engine idle.
Whats the point ?
BTW : dnsey
They are not really steppermotors despite the designation. They are simple DC gearmotors.
Only the very early types where in fact steppers with the elaborate electronics for controlling the motor position.
Was way too expensive in the production, thus abandoned.
Anders (DK) - '90 BX16Image