406oc.co.uk

Had a few problems with my car while I was away and they returned when I got back! The car cut out in a car park, I couldn't restart it without pressing the throttle and when it did start the idle was very erratic, would drop below 500rpm and nearly always cut out. Had the AA out and they sprayed what I believe to be carb cleaner into some pipework and over the stepper motor. He believed it was either the stepper motor or a map sensor. I went to a local garage and they had the car for a day and claimed to have found no fault with it, it apparently never cut out when they tested and drove it, all they found was a code for the knock sensor and promptly charged me £95 in total. The car did appear to be fine but yesterday at a junction I noticed the idle was very high, was around 1500rpm. Drove it home over 120miles today and no probs. Was in my flat for around 30mins when we got back, went back out in the car and it started all over again. Every time I stop the idle drops ridiculously low, tries to level out but fails and promptly cuts out and I need to touch the throttle when restarting the car, I've revved it, been gentle slowing down and pressing the clutch but it keeps cutting out. Now I've looked at parts on ebay and I can get a stepper motor for around £20, around the same for a map sensor. is there anything else that can cause idling problems? Skint after my honeymoon and won't be able to get it into a garage for 2 weeks.

Hi Lee had the same trouble twice with my 2.0 petrol. crap idling and stalling and both times it was the stepper motor ,once changed no problems PS do it it yourself takes ten minutes but make sure you resynchronize the stepper motor when youve fitted the new one

Cheers Rob, been fretting about it costing a fortune since it happened lol. I'm not a mechanic and I probably won't try myself, but how and why do you need to synchronize it?

Hi lee dont know why it has to be done but if you look on the... engine and transmission page there is a Sticky about 406 petrol Running and starting thread it actually shows where the stepper motor is

When i changed mine it revved up to about 2500 rpm on its own i restarted it a few times and the it settled down to a perfect idle. What is the proper way to synchronise them ?

Other than that dead easy to do worth cleaning out your throttle body at the same time, i put paper towel down the body to absorb a lot of the carb cleaner i then leave for a while to evaporate as i worry about damaging the cat . Not sure if it would though just dont like to risk it.

matt

Well I've just had a quote from my regular local garage, not a big place just an independent family run one and they've quoted me £66 labour for the motor and £96 to fit a centre box as well. I think they've quoted an hours labour for the motor as it was £55 plus vat. Not impressed, I will have to try elsewhere or just bite the bullet and pay it.

Send Roylewa a pm.
He had a stepper motor for sale,

hes not been on in awhile,
might be worth asking him if hes still got it,

viewtopic.php?f=7&t=18336

When a stepper motor is fitted the ECU has to then adapt to the new part. Once fitted and you start the engine it will usually rev quite high but will settle down. Fitted one to a xsara i had and thought i had stuffed it when it scremed it nuts off but it did settle.

both map sensor and stepper are easy to fit and from past experience have nearly always been the culprit behind bad idle etc.

Thanks! Have message Roylewa about it!

Well I didn't get a reply so I bought one off ebay. Cost me £35 and a friend is fitting it for me this weekend hopefully. The car has been better the last couple of days but I don't trust it!

Well I fitted it myself on Saturday and followed the instructions on the forum, I am still a bit concerned though, how long should it take for the idle to settle fully after fitting? I've been out for a long drive in the car, through traffic, down a motorway and its still not quite right. Driving home sat night and when I stopped for traffic lights it nearly cut again, revs dipped really low and then suddenly came back. By the time I got home it was better, I tried revving it and dipping the clutch but I couldn't make it cut out. If the new stepper hasn't cured it, how easy is it to change the map sensor?

Did you get the problem solved ?