A different stepper motor question

[darthPaddington]

Ok so the TVR isn't idling properly and keeps stalling.

:idea:
I know what to do thinks I and removes and cleans the stepper motor - many thanks to [url]south wales TVRCC|http://www.tvrcc-south-wales.co.uk/stepper.asp[/url] it all seemed to go fine and I removed lots of carbon. I also remembered to clean out the hole

Now it's all gone wrong and the car won't start.:confused:

Can any one help please.

[Nuggs]

Have you plugged the electrical connector back in?

[GreenV8S]

If you switch the ignition on and then off again without starting the engine, do you hear the stepper motor chuntering away to itself? Stop me if I get too technical ...

[darthPaddington]

the electrical connector is in

I've lstened to the stepper motor (first time ever) and heard a new noise when the ignition turns off there is a little buzzing noise that seems to come from the stepper.

it seemed to get a little closer to starting this time.
it sort of coughed and gave clouds of smoke

this is worrying

[darthPaddington]

Ok, as it's getting late I thought it might be worth giving it another go...

there was no buzzing noise from the engine.
It started quicker and easier than usual and sat there ticking over nicly.



tomorrow I'll take it out for a good thrashing

[hut49]

Hold the thrashing - if you've changed the stepper profile by removing all that carbon you'll need to give the ECU a chance to reconfigure itself with all the new input it will get from the various sensors affected by the new airflow characteristics. So take it easy and keep below 3500 revs for the first few hours so it will get to know the new operating paradigm.

[GreenV8S]

hut49 said:

Hold the thrashing - if you've changed the stepper profile by removing all that carbon you'll need to give the ECU a chance to reconfigure itself with all the new input it will get from the various sensors affected by the new airflow characteristics. So take it easy and keep below 3500 revs for the first few hours so it will get to know the new operating paradigm.

Huh?

[griffter]

darthPaddington said:

the electrical connector is in I've lstened to the stepper motor (first time ever) and heard a new noise when the ignition turns off there is a little buzzing noise that seems to come from the stepper. it seemed to get a little closer to starting this time. it sort of coughed and gave clouds of smoke this is worrying

Did you inadvertently knock something whilst cleaning the stepper?

For example the fuel pressure regulator vacuum line to the plenum? Check that's in place and that the plumbing & wiring to the injectors looks OK.

[GreenV8S]

Sounds like the problem has 'gone away' which is a relief. Perhaps it was as simple as flooding the engine, which then needed time to dry out before it would start.

I'm sure it's OK but do just double-check that you can still hear the stepper motor park if you switch the ignition on and off. If not it's no biggie but means the idle speed won't be controlled by the ECU so it will idle slowly/not at all when cold, and fast when hot. To be fair that is actually better than the random idle control you get when the stepper motor is playing up ...

[darthPaddington]

many thanks for the help.

I went out early this morning (in the fog) and took the car out through a bit of fast road and along through the city.

initially it didn't seem happy with me pulling away (probably nervs on my behalf) but after that it performed well. I've been out again and there was none of the hesitance from the first time.

I'm sort of assuming that while cleaning out the carbon from the housing I must have pushed some of it in to block the system and it needed clearing out.

in the end though what I had was a few failed attempts to start followed later by a scary coughing start and a big cloud of smelly smoke.

It's great to know that there are people out there willing to lend a hand, or even a sympathetic ear.


Cheers

Peter