Stepper Motor

[Freddie]

My Saxo can have problems 'hunting' (I think this is the term) when the engine is warm and the automatic choke is bypassed, the car will not always idle correctly and sometimes cut's out.

My car is going on the diagnostics machine this Friday, but I think one of the main causes of this is the stepper motor. I wanted to clean mine, or swap it for a new or reconditioned one. I was wondering if much mechanical knowledge was required to do this?

The garage wants to charge me £117 + VAT and labour (I assume) and I thought this was a bit dear.

Freddie.

 

[obi_waynne]

Stepper motor problems seem to be quite common. Ive seem quotes to fix this at £170!!!

Have you done a search on Ebay - I've seen them for £40 (Its about £80 from Citroen) but don't know what sort of job it is to install the thing!

Found this info on a pug website:-
Cause:
Manufacturer deviation in the specifications for the throttle body
It recommends checking if there is a white spot on the top of the plastic throttle housing if not - replace it with Part No 1635Q0.

 

[Freddie]

Thanks Wayne!

I've had a quick hunt on eBay but nothing surfaced. I will let you know how the diagnosis turns out tomorrow and what route I will follow.

 

[billyo]

Freddie- It's always worth trying the local scrappy - it's the sort of thing that they don't really charge much for - they prefer selling gearboxes and heavy stuff like that. Good luck man - fingers crossed for you.

 

[Freddie]

The diagnostics results came through with no problems.

The mechanic decided to clean out the inside of the throttle body (which I had tried to do myself, apparently unsuccessfully) as the butterfly was sticking and not letting enough air through at idle. They cleaned right down deep inside. When they started it up they gave it alot of revving and the engine started popping. It sounded pretty nasty but apparently it was all of the unburnt particulates going through the injector system.

I think the cause of this might be the fact I have an open air Piper X induction kit on the Saxo. It was already on when I bought the car and hopefully when I get paid next I will buy a standard airbox from a scrappy.

It seems to be almost perfect now but they ended up charging me over twice as much I expected without asking me for them to do the work. Hehe, oh well still cheaper than buying and fitting a whole new stepper motor.

Thanks for all your help guys.

Freddie

 

[obi_waynne]

Phew - lucky escape. Might be worth doing an oil change - a lot of the junk gets swept along into the oil! It's best to get it out of the engine ASAP especially if there are and small metal fragments created by the cleaning process although its most likely the garage used some heavy solvents rather than a hammer and chisel.

 

[Freddie]

I don't know if I'm just being paranoid, but it feels as if the problem is re-developing itself, even after a few hundred miles.. I might be going mad but I think I'll get that air filter sorted as soon as the next pay-cheque comes though!

Thanks for the advice, what sort of oil is best to go for in a small-engined car, such as mine?

 

[Freddie]

I managed to get hold of a brand new airbox from Citroen. I phoned all the scrappys around but they were all to pricey or didn't have the right part..

I've tried to clean up my throttle and sensors today with a bit of carb cleaner (half heartedly I'll admit, as I was in the middle of cleaning my whole car) and fitted the air box.. Bit of a bodge job at the moment as I didn't have all the connecting pipes. Theres one I know I need which goes from the waste gas (?!) release in the rocker cover to the air box.. And there's another gaping hole in the air box, around 800mm across, underneath the main intake. I have no clue what this is for but it's taped up with gaffer tape at the moment!

But over all I'm please with it.. Engine is alot quiter now, and doesn't vibrate as much.. Also I thought the car was misfiring when it was decelerating at around 2k RPM but this has completely gone now..

Oh and just to ruin all my hard work.. It's decided to rain straight after I've just washed the pissin' car!

 

[Sid447]

This is a common problem with NON ETC cars,

(Electronic Throttle Control). Because of the emissions requirement for all crankcase vapour to be fed into the engine to be burnt. Some manufacturers feed the CCV into the intake tube before the throttle-body and this over time gums up the throttle-blade or butterfly and also gets sucked into the IAC (Idle Air Control or called stepper here) motor port. In fact when the engine is at idle or over-run (TP closed) all this vapour will going through the IAC port only.

Regular cleaning with either carb cleaner fluid (or good old paraffin/kerosene works just as well) and a non-fluffing cotton rag and 1/2" paintbrush will keep the surges and idle problems away associated with this problem.
It's probably more effective actually removing the IAC motor to clean it and the port in the t/body.