Colin, Tim & other techies, this stuff is really interesting & SHOULD be published in Miscellany, I often hear of 'modern' Mogs with MIL warning lights stuck on
Regards, Jon _____ From: e-mail colin.jones5857 [mailto:[email protected]] Sent: 11 May 2012 15:38 To: mogtalk2 Subject: Re: [mogtalk2] Miscellany Hi Owen No thanks required at all, just the thought of another worry gone is thanks enough ;-). I did not come up with all these fixes alone either, many are the work of several of us spanner jugglers working together being real nerds sending emails in the night about codes and misfires and to be honest just plain and simple detective work. Just to help you sleep here is the story of the EVAP diagnostics and conclusion. On holiday in France with Christopher BK, Richard Rebain and wives. I arrived last at the Gite and JUST after filling up, that's a misnomer as the petrol attendant filled the car and was so busy admiring he washed the back of the car with petrol, it was overflowing from the filler neck! (don't think the village had even heard of blow back arresters on the pumps!). Anyway after throwing his screen wash bucket of water over the rear of the car I drove off, no problem. Next morning, off for a drive, 3 miles down the road and the car sputtered coughed and almost stalled.....then it cleared and was fine for 30 seconds and did it again....5 or 6 times so I returned to the Gite to think.......(and panic). OK, the feeling was just like someone pulling out the choke and there was a strong petrol smell, it was a soft chop (electrical faults feel hard, fuel feels soft) Could not see anything of course so started to think where excess fuel could come from. On a whim I unplugged the hose from the EVAP purge valve and it was full of fuel. I shook out what I could and started the car. Stood watching it run then hunt and cut then run etc. etc. it was clear it was cyclical. I made a test lamp from a spare bulb and wire and bridged the electrical plug on the purge valve and started the engine, the bulb lit when the purge valve was energised and a couple of seconds later the car spluttered,the bulb went out and again after 3-5 seconds the car cleared. I then had another think, syphoned out one gallon to lower the fuel level, had a terrible job getting the EVAP canister out and emptied another pint of fuel out of it, left it to dry in the sun, blew through the purge lines and reassembled. Problem gone, it only ever happened once more after I had overfilled the car by mistake with a fuel can and then I left it running to purge itself. Fault finding is just gathering evidence and understanding the systems. Lots of fault codes are not actual faults its just that the programmers set parameters and if the system steps outside of allowed values the code is stored. Later systems are far more sophisticated and have a priority learn function, that is if its a none safety related code (and even some safety like the BMW ABS low voltage codes) if the system sees 5 cycles of no more code found it wipes the codes and puts out the warning light. Some codes (like the multiple misfire) is used to cover a multitude of sins as just about everything we have discussed as a possibility for your car would look to the ECU as if its been caused by a misfire, hence the code stored. I don't always know the answers but am always happy to help or at least try to, these systems are really good you know, its just that we did not have fault codes on good old carbs and coil ignition systems or we would have had even more codes stored ;-). BR Colin ------------------------------------------- View posts on The Mail Archive http://www.mail-archive.com/[email protected]/ [http://www.mail-archive.com/[email protected]/] Modify Your Subscription: https://www.listbox.com/member/?member_id=22459785&id_secret=22459785-4a39ddf8 Powered by Listbox: http://www.listbox.com
