306 irregular idle speed

[Anders]

My 1999 Peugeot 306 has got its own personality. When I drive slowly (under 70 kmh) it periodically speeds up by itself. Also when it is just ideling, RPM varies between approximately 1000 and 2000.
My local Peugeot dealer has (among other suggestions) suggested that the ignition coil has knocked out the Ignition Controller (ECU). Since that is a pretty expensive part compared to the value of the car, I would like to know if anyone has experienced something like this - and found a solution :blink1:
I also want to know if you can just replace the ECU, or if you need to replace or somehow match the ignition lock with the new ECU.
Thanks in advance

 

[jarrus]

I don't see how it has affected the ECU because the 1.4's and 1.6's use dizzy caps and igintion coils.....

Take it to an independant garage for them to check it out.

 

[Anders]

Well jarrus, I don't know what a dizzy cap is, but after a few hours of googeling I'm convinced that the ignition coil does backfire and blows the ECU in my kind of car.:sad2:

Thanks anyway.

 

[T9 man]

Well jarrus, I don't know what a dizzy cap is, but after a few hours of googeling I'm convinced that the ignition coil does backfire and blows the ECU in my kind of car.:sad2:

Thanks anyway.

A dizzy cap is a distribution cap my friend, and I can assure you that despite your google searches to the contrary, if Jarrus tells you something about a Peugeot then you can pretty much accept it as the gospel! You might do well to listen to him and heed his advice

 

[jarrus]

wow.... cheers T,

I wouldn't say I know everything about Peugeots though..... but I do know a fair bit....

Distributor cap is the bit that is attached to the top of the coil pack and isn't ECU controlled and very easy to replace, would be my first port of call before spending loads of money.

 

[Anders]

Thanks a lot to both of you T9man & jarrus. A car that is ideling and suddenly increases its idle speed from 1000 to 2000, do you really think that could be caused by the distributer cap??? I do know what a distributer cap is, but I would never have thought of it as a possible cause for that behaviour. Besides, the car is equipped with an "IGNITION COIL RAIL PACK" - so where excately does the cistributer cap go? I really don't want to offend any of you, but for now I think I'll go for the ECU. I'll let you know how it goes.

 

[jarrus]

Depends upon the year of your car mate, early ones have dizzy caps, after that then I would think they use some kind of wasted spark, maybe....

I have seen stranger things happen, Ford used dizzys and rotor arms on the Cosworth engines......

 

[jarrus]

found this on the net....
voltage Spike from the Ignition Coil which is a common fault on the 1.4 engines, it will need to be replaced.
If you have a sagem coil then replace it for an electrifil unit especially if your car runs a Sagem sl96 management system as Sagem coils are rubbish and cause all sorts of electrical problems such as you describe.

 

[Anders]

Thanks pal. Yes, more and more point in the direction that my local Peugeot dealer and my own Googling could turn out to be right :blink1:. The old ECU is a SAGEM 96-9, and the new one I ordered is internally upgraded to "Marelli". Should be roboust - as oppose to SAGEM. I'll let you know how it works.

 

[Anders]

Hi Guys,
The ECU has now ben replaced. I bought a refurnished one from ecutesting.com in the UK. It took a while to get it, but I got it, the immobilizer was disabled, so I just pluged the new one in - a five minutes task - and were up and running. And it fixed the problem.
Thanks a lot for your engagement.