Stepper motor

[simon t]

My Griff is hunting on idle quite a bit at the moment so I took out the jolly old stepa mota and gave it a clean. Put it back and fired her up. no change, checked under the bonnet and realised I had not reconected it. Plugged it in and no change to the engine speed or hunting. Tried to start up from cold with it disconected then connected it no difference.

Question is should there be a noticiable difference between it connected and not connected? Has me stepa mota taken its last pace? any other ideas about the hunting?

[vodkakid]

hello
try giving the connector on top of the air flow meter a wiggle with the engine running
andy

[snowy1101]

Can some one tell me what a stepper motor is and where it is to be found. Having read a number of threads on here about it it seems that I should know where and waht it is as I may need to do something with it sometime.

[shpub]

You have a Tuscan. Tuscans don't have them. Stepper motors are only applicable to Griffi, Chimpi, V8Sii i.e. Rover V8 engined cars.

[mav]

Ok.. two things
1. disconnect and re-conect the ecu when you have played with anything to do with the engine management as it needs to re-set itself.
2. If you travel at say 30mph and knock the car out of gear, what revs does the engine do?

Mav

[simon t]

Mav,

already reset the ECU. when the engine is in netral the revs drop down to about 600 rpm the pick up to anywher between 800 and 1200 rpm.

anyone know how to test the stepper motor to see if its stepping?

[david beer]

If you turn the ignition on and then off, not starting the car, you will hear it buzzing in and out. If it wasnt "stepping" you would not be able to start from cold unless you had a bit of throttle. Anyway thats my theory.

[andy43]

My griff was 'hunting' so I cleaned the stepper motor and it's now smoother idling. With the stepper plug unplugged on mine the idle shoots up 1500-2000rpm and upwards - when the stepper is removed and hence unplugged the plunger bit is right in without the electric applied - try running the car with the stepper removed from the plenum, but plugged in and the hole in the plenum blocked with a rag or something - see if the plunger moves? A bit longwinded and I didn't try this with mine 'cos it works but may be of some use?
Edited to say Aah-ha so thats wot that buzzing sound is from the engine!

>> Edited by andy43 on Saturday 26th April 12:56