306 Stepper motor clean

I use aerosol brake cleaner. Make sure the ignition is off and remove the stepper motor (small torx screws,and can be tight). spray the cleaner over the piston and allow to dry. Also spray into where the piston goes, but not too much. Put the stepper motor back. Start the car and rev it to 3000 for 10 to 15 seconds, just to clear the cleaner out. Now allow to idle. If it stalls, or idles too high, it needs to be initialised. Switch off the engine, switch on the ignition, then off for 10 seconds, then on for 10 seconds then off. Now start and see how it idles. If necessary repeat the operation. If it is still messing about, switch off and disconnect the battery, then the ECU and leave disconnected for a minute (make sure you have your radio code!!). then reconnect the ECU, then the battery, then repeat the initialising operation again. That will hopefully do it. If not then you need a new stepper motor.

Nigel, Does this method generally hold true for other models? I have a 94M plate 1.8i 405 which very occasionally decides to idle at

TIA

Bob

Well, I think this model has an idle valve which is located adjacent to the distributor/coil pack. You can take it off, and use brake cleaner, and use a small screwdriver and GENTLY make sure the valve rotates inside. You do not need to initialise it. Just start the engine and rev it to 3000 to clear the cleaner, and that should do it.

"Nigel" schreef in bericht news: snipped-for-privacy@4ax.com...

I have the same complaints as the OP. But the (garage)diagnosis says that the "ignition system has been permanently damaged" and will cost a new ECU. Cleaning of the steppermotor has not mentioned as a solution. What I do not understand in OP's story is why he thinks its only a matter of some cleaning? And what contamination will cause a change of the idle revolutions now and then? Is the petrol not pure enough? But I am willing to try everything to avoid the replacement of the ECU, therefore I should like to clean the steppermotor .But Nigel mentioned the resetting of the ECU by disconnecting the plug from the ECU. I tried this, but I could'nt take off that plug....

Thanks Nigel. The valve is pretty obvious alongside the rocker box. Not sure if it is a stepper motor type (bosch motronic 5.1 ECU). I lookout for some of this brake cleaner and give that a try. Presumably WD40 is the wrong stuff to use? as I have some already.

regards

Bob

NO don't use WD40 as it will leave a deposit in the valve. You need a solvent which will clean and then evaporate away. Brake cleaner is ideal and only costs a quid from a Peugeot dealer. Or should do. Halfords sell it too.

Hi Nigel,

Many thanks for you're detailed response. I'll get some brake cleaner over the weekend and give it a go. You mentined about a piston

spray the

Where abouts is this piston? Inside the hole where the motor came out from? Does the motor have a cog on the end of it?

Many thanks once again!!

Matt

Well, I call it a piston, but it is probably called something else! It's part of the stepper motor, and you will see it when you remove it--the shiny thing on the end. At least it SHOULD be shiny. It is probably carboned up. Give it a good clean with brake cleaner or carb cleaner, as Yuting Wan said. Please do not be tempted to connect it up and turn the ignition on to make the piston come out further. It may come all the way out and you may have a hell of a job getting it back in.

Hi Nigel,

Just to let you know that I took out the stepper motor sprayed carb cleaner in it and clean the end of the motor and now all of my problems have been sorted. The car will idle fine and allow me to put it in 1st gear release the clutch and the car will drive it's self fine, before it would bulk and try to cut out etc.

Many thanks for you're help you've saved me about £100 if I took it to a garage!!!!

Cheers

Matt

No probs. Glad I could help.