starting problem after cleaning stepper motor

[johndvh]

Hi you all,

I noticed that my 400SE (hotwire) had some idle issues. As I never cleaned the stepper motor before, I decided to give it an inspection. When removing, the cone was screwed in totally and quite dirty. A bit of WD40 did help a lot and I unscrewed the cone to clean everything. Checked it's operation by plug the connector and turned on/off the ingnition key to I. (not starting) it operates fine and the cone is moving inwards. As it was already late, I did not start the engine.
Today I did try to start the engine, if fired right away (as usual) but stalled within seconds. Doesn't want to start anymore. Checked on operating again, but works fine. Tried the ECU reset trick (5-times throttle) but did not make any difference. Any tips?

Cheers!

[mrzigazaga]

Hi mate...As far as I'm aware the stepper motor can fail where the connections are on the unit...Most are subject to heat and cook...The operation may still work but not send the correct signal...Hopefully someone who is a bit more knowledge in the hotwire can help more...Ziga

[mrzigazaga]

Hi ...Just spoke to a friend about this and he said if you have wound it out too much to clean it then it will need re-cycling with some software like Rovergauage or ECUmate...It needs to be wound in and out by this to prove operation....Hope this helps...Ziga

[johndvh]

well,to be precise. I first only cleaned it (no adjusting of the cone) than the problem occured. Removed the stepper motor again to check if it is stuck. Had some resistance for the first turning and screw the cone out. Am i'm looking at a replacement?

[ElvisWedgely]

You should be able to hear the stepper motor when you switch the ignition on. If it winds in and out then the chances are its fine. There could be a problem or a couple of other problems elsewhere. Ignition module and coil can be suspects. It could also be the ignition leads, plugs or cap. Possible air leak, or maybe the throttle body needs a clean out. It could even be the earth lead. It is very difficult to diagnose but you must try the simple things first methodically. If you do need to replace the stepper motor, fit a good make, not a Chinese copy. Good luck.

Tony. TCB.

[mrzigazaga]

Unfortunately I'm not familiar with the stepper motor but the friend who advised me is...Just because it goes in and out doesn't mean its working properly...It needs to be re-calibrated if its been manually wound out and cleaned!...A new one is around £90 and will still need to be calibrated.

[ElvisWedgely]

The stepper motor is infact a stablisation valve found on many modern cars. It's purpose is to act as a choke mechanism on start up and supply correct amount of fuel to help the idling.

I owned a V8 Wedge with the stepper motor completely disconnected and it still run fine. The only draw back being the there was no choke mechanism on start up, so it would take a while for the car to idle until the car was warm enough. My point being that the car will start and run even without a stepper motor, let alone one that doesn't work properly. Stepper motor contolls starting and idling. If your car fails to run then you should be looking elsewhere in my opinion.

Tony. TCB.

Edited by ElvisWedgely on Monday 30th May 11:04

Edited by ElvisWedgely on Monday 30th May 11:07

[mrzigazaga]

Could also be a Lambda sensor.....Or an air leak...Or....As said I'm not familiar with the system and only pass on what i have beed told...

This may help you...
http://www.g33.co.uk/fuel_injection.htm

Cheers.

Ziga

Edited by mrzigazaga on Monday 30th May 11:39

[johndvh]

Thanks for all the suggestions. However, as a basic approach; it works fine; cleaned the stepper motor; doesn't start. Then the best starting point is stepper motor related rather than the other suggestions (which seem plausible if it just doesn't want to start overnight) Otherwise diagnosis gets complicated i suspect. As i inspected the gasket of the stepper motor, it seems to be a bit worn out (overtightening) so i will grab a replacement on the way home tonight and see if this causes an air leak.

[ElvisWedgely]

johndvh said:

Thanks for all the suggestions. However, as a basic approach; it works fine; cleaned the stepper motor; doesn't start. Then the best starting point is stepper motor related rather than the other suggestions (which seem plausible if it just doesn't want to start overnight) Otherwise diagnosis gets complicated i suspect. As i inspected the gasket of the stepper motor, it seems to be a bit worn out (overtightening) so i will grab a replacement on the way home tonight and see if this causes an air leak.

Not necessarily. There may have been another underlying problem causing the bad idling before you opened the stepper motor. Now magnified by disturbing this component. By all means, satisfy yourself that the stepper motor is not the cause before you disturb anything else. My guess is, you have another undelying problem perhaps in conjunction with the stepper motor. Like I said earlier, I had a hotwire V8 wedge that ran fine without one.

Tony. TCB.

[TVRleigh_BBWR]

what you may want to do, just to get yourself running again is to wind it back in again, and then re-connect with the wires disconnected, see if it runs, idle maybe very high. if so you may need to get it re-programmed via rover gauge.
I think there is another way to calibrate do a google search.

[johndvh]

Tried last night. replaced gasket and turned the ignition key 5 or 6 times on/off till the stepper motor stopped "ticking" (should be in base position than i guess) She started with the second attempt. Did 1600 rpm but quickly went to 1200 - 1000 (as normal) Due to the rain i did not made a test drive. I don't suspect that the gasket made that much of a difference, so my guess for now is that the stepper motor was too far off to make it burst to life. Fingers crossed for the test drive.

[johndvh]

Tony, I think you are right.
Tried to start here up again, same thing happend as before, runs for 2sec and cuts off. I understand multiple options to assess. Immobelizer led goes out (fuel pump is not cranking otherwise) and the inertia switch is down (had this before) First to check is the relay. Can anybody give me a hint which one to check on a hotwire? I understood that is supposed to be marked with red stripes?
Cheers!

[ElvisWedgely]

You need to establish if it's electrical or fuel problem. If electrical, you should be looking at, leads, cap, coil, ignition module, disributor, coil, ecu etc. If fuel problem, you should be looking at fuel pressure, regulator, pump, injectors etc. More or less like any other early fuel injection car.

Tony. TCB.

[mrzigazaga]

Even if it has gone through the winding process it still may need recalibrating to the ECU.....You need ECU-mate or Rovergauge to re-calibrate the motor.....

[andy43]

The stepper, if it zuzzes on ignition on, should be reset and forced back against it's stop - unless it's bust. If it's the same stepper as the Griff, the cone can't be manually screwed in and out at all as it has a groove in it - it just moves straight in and out as it's pushed/pulled by the motor thread. The only way is to use rovergauge or ecumate to power it in and out. That 'resistance for the first turning' might be what's caused the problem as the cone will just spin round and stay in the same position if the groove/keyway has failed.

Eta good pics/explanation here http://www.gomog.com/allmorgan/StepperMotor.htm

[johndvh]

I can confirm that the stepper motor does work (not if it works correctly however) is it turns in if you remove it and reconnect it. As Tony indicated, this should not be the main issue.
I checked and i do have a spark, but the sparkplugs stay dry. Fuel pump is priming, so first to check is the fuel relay. I saw about 12 relay's in the passenger side, can anybody give me a hint how to find the fuel relay as none of them is marked? Couldn't find the answer in the wedge bible. It's a hotwire. (found flapper pictures with the search)
Cheers

[mrzigazaga]

Hi John...The "Steering module" relay is the only red one there...Its a "Pektron"....Although i cannot see it being that if the fuel pump is working.

You still haven't calibrated the stepper motor with the ECU with any form of software and until you do then you shouldn't even start looking else where...You will just start creating more problems for yourself!.....100%

[ElvisWedgely]

mrzigazaga said:

You still haven't calibrated the stepper motor with the ECU with any form of software and until you do then you shouldn't even start looking else where...You will just start creating more problems for yourself!.....100%

I would agree with you if his problem was idling or cold start up, but in his case the car starts, stalls and won't start again. The car should run quite hapilly even without a stepper motor, let alone one that doesn't work right. I know because my previous wedge had a disconnected stepper motor. It won't harm it to calibrate to the ecu but I don't believe that is his running problem. It's something else, or as well as. My bet would be on something like the ignition module as I had simillar symptoms when the ignition module failed on mine. Just my opinion.

Tony. TCB.

[mrzigazaga]

ElvisWedgely said:

The car should run quite hapilly even without a stepper motor, let alone one that doesn't work right.
Tony. TCB.

Yeah if you are happy chucking a ton of fuel in...

The fact that the motor was "Manually" wound out could be the issue...There is a sequence to removing these units....And even if it has clicked in and out a hundred times it may still not be recognised by the ECU...But crack on...Start replacing parts that are not needed...Spending money chasing problems that don't exist!....Good luck.