Petrol Diagnostics

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Peugeot 307 2.0 RFN Petrol 2002 - Runs rough after a couple of minutes #

Posted by Mark Dyson on November 20, 2009, 11:19 am

Year of Manufacture *: 2002
Engine Code or CC *: RFN

This car starts from cold fine and then after about 1 or 2 minutes of running it will run very roughly as though over rich. It does this for about 30 secs and then settles back to pretty normal for the day once hot!

Its been to both dealers here in Perth Western Australia who have given up basically. I found the injector O rings were mangled and the plug gaps were double the specs. Correcting both has improved the idle but the problem persisted.

I have a Pico scope and found that indeed when the engine is running roughly the pulse width goes off the screen and by the time I'd fiddled with the time base to get it on screen the pulse width was coming back to normal and the engine starting to run ok again. Even when fully warm the width is about 4.25mSec which is very slightly higher than any other car I've checked as they are invariably 3.5mSec.

I haven't monitored it from a cold start as yet and looking at the oxygen sensors waveforms was inconclusive to me at least! As I've found oxygen sensors can do strange things I tried some new ones however the problem remains though the idle once it settles again is smoother.

Maybe the MAP is momentarlily giving a false reading with the first glimmer of heat in the engine?

Any ideas or am I missing something? It seems to me that something is telling the ECU to grossly increase the pulse width for that period or maybe an ECU problem. If so it would be the first one I've ever had in 12 years, hence I'm sceptical.

The dealer advised the owner that the problem was a mechanical one requiring the cylinder head to be removed. I'm not convinced to say the least as I cannot think how anything mechanical could be so transient.

Hope someone can assist!

Mark Dyson

Re: Peugeot 307 2.0 Petrol

Posted by Glyn Morgan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2543' width='330' height='300' border=0 style='border:none;'> on November 20, 2009, 1:33 pm, in reply to "Peugeot 307 2.0 Petrol"
Glyn Morgan

Hi Mark

I have had this on 307/206 models, I suspect your problem is being caused by the hydraulic tappets.
There is a modified tappet available.

If you monitor the engine vacuum when the fault occurs you will find it drops, the ecu thinks the engine is under acceleration due to the MAP sensor value & extends the injector duration.

I think there may be some more info in the archives. HTH

Regards Glyn

Re: Peugeot 307 2.0 Petrol

Posted by Mark Dyson <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2718' width='330' height='300' border=0 style='border:none;'> on November 20, 2009, 2:32 pm, in reply to "Re: Peugeot 307 2.0 Petrol"
Mark Dyson

Thanks for that Glyn, makes sense!

I've heard rumors of such things on 206 especially if the wrong oil is used in them but never have come across it myself.

This car is way overdue for a service as well, surley it couldn't be that simple! I'll have a look in the archives and look at the vacuum as you suggest.

Thanks for the input, I must admit to not thinking of such things! Never a dull moment eh!

Mark

Re: Peugeot 307 2.0 Petrol

Posted by Liam Boyle <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5195' width='330' height='300' border=0 style='border:none;'> on November 20, 2009, 4:35 pm, in reply to "Peugeot 307 2.0 Petrol"
Liam Boyle

I would imagine this has been checked already but have you scoped the coolant temp signal to the ecu throughout the warm up period? I had a Renault do something similar where the temp sensor signal would give a false value not long after first starting up but still plausible as far as the ecu was concerned so didn't throw up any fault code. Other than that I have had other variable valve timing problems (Rover VVC!

) causing engine vac problems and obviously upsetting fuelling due to manifold vacuum change/compression etc so the hydraulic lifter issue could well be the problem. Any chance of getting 4 gas readings before during and after the problem occurs?

Liam

Re: Peugeot 307 2.0 Petrol

Posted by Tony Ludford <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5539' width='330' height='300' border=0 style='border:none;'> on November 20, 2009, 8:06 pm, in reply to "Re: Peugeot 307 2.0 Petrol"
Tony Ludford

As Glyn has said, Peugeot have a technical bulletin for tappet problems on these. They replace them with tappets from the EW 2.2 engine