16 replies to this topic

[Bristolmini]

I've had the inlet off to change the lamda sensor and since then I can't get the car to idle. Looking at where the stepper motor is it doesn't appear to come out of the housing enough to control the idle speed.

If I take the little rubber boot off the stepper motor there is a thin shaft, maybe 3mm diameter but it only seems to stick out about 4mm so not even right out of the rubber boot.

Does this sound right or is there something missing?

[minidaves]

reset it as per haynes manual

dave

[Bristolmini]

I take it resetting it is key to Ignition on, fully open and close throttle (from engine bay) then start.

If so I already tried that and it didn't do anything.

It all worked fine before I took the inlet off which is quite annoying

[minidaves]

have you got the air pipes on the back of the manifold on correctly?

also have you adjusted it as in the little lever thing at the back when you reset it?

dave

[Bristolmini]

all the air pipes are on correctly

Adjusted the lever thing? is that the adjustable 'plate' which makes contact with the stepper motor ram?

If so, even if I adjust it all the way out then it still won't touch the stepper motor ram. With the rubber boot on you can't see the ram from the stepper motor at all.

[Sprocket]

http://www.theminifo...ic=20533&st=11#

See how you get on

Also worth noting that when the ignition is switched off the stepper motors to full step positions ready for the engine to start the next time. This can be heard as several clicks coming from the engine bay.

it may be that you do actualy need to tune the system with a diagnostic, but not being able to see whats going on its going to be difficult to diagnose.

I helped msisleman out the other day. the stepper on his was at zero steps and the idle was up at around 1000, the whole system needed to be re tuned. Just waiting on confirmation on the other problems he had to resolve

[Bristolmini]

From the pictures on there it definitly looks like the stepper motor is not moving out enough, I will have a proper play this week and see if I can get it any better, It was working so hopefully I will be able to ressurect it.

[Sprocket]

Not being daft but you have plugged it in???...

[Bristolmini]

I have plugged it in, one of the first things I checked.

[Sprocket]

If you think it is actualy duff, i have a couple that i can check to see if they are working right. If you need one that is.

[Bristolmini]

Are there any sure fire ways of testing the motor to know if it is the motor itself or something controlling it which isn't right?

[Sprocket]

Can you hear the clicks when the ignition is switched off?? you should see the plunger like in the pictures with the ignition off. Other than that its a diagnostic and tune.

The stepper can be removed from its housing and you can see the cam inside that operates the plunger moving. If you go this way, remove the torx screws only, there are three posidrive screws that hold the motor to the lid, leave these.

One other thing is to try and reset the ECU. Not had any sound information that says this actualy works but might be worth a try. The stepper may not be motoring because the ECU is telling it not to as the ECU had tried to adapt to the incorrect tune of the throttle. Disconnect the ECU from its connector for a few minutes then reconnect it. This should (suposedly) reset the adaptive values.

I'll ad some piccys in a bit

Right, to remove the stepper motor from its housing, it is necsisary to remove the injector and regulator housing first.

Clamp the hoses


Then disconnect the unions with a 15mm and 17mm spanner


Then remove the four large torx screws


And withdraw the housing


The four torxs crews for the stepper can now be removed, note two also hold the linkage bracket


Here you can see the plunger, the cam and the motor clearly


This is another manifold i have. I have removed the rubber boot to give you an idea as to where it should roughly be position wise.

Edited by Mini Sprocket, 27 February 2006 - 11:53 PM.

[Bristolmini]

didn't notice any clicks when turning the ignition off, the plunger is way back inside the rubber boot, can't actually see any of it at all.

Will try resetting the ecu as well, easy to do and if it just might work it's got to be worth a go.

[Sprocket]

Pictures added, check the post above.

[Bristolmini]

My stepeer motor definitly needs to be further out. Half the amount, if not less of the plunger is showing on mine.

Luckily I have a day off on Thursday si I will be able to try all these suggestions and see if it cues the problem.

Thanks for all your help, some real useful knowledge and always happy to offer it.