406 gtx 16v "petrol"cold start missfire!

[kal]

Hi guy's ,got a problem i hope you can help me with .starting from cold ,no problem drives fine ,then about half a mile goes into limp mode.Have checked engine ecu with my tester and it reads as follows"misfire on number 3 cylinder".As you all know ,this could be caused by a number of different things ,sensors an that ,so i sort a second appinion. so off we went too a local garage,who use crypton cmt checks.Talked to mechanic after he'd checked her ,and the results are this "stored fault codes po300 random/multiple cylinder misfire ,missing on coil pack,sorted i here you all say ...no!!tried that idea already fitted new coil pack a few weeks ago !The mechanic said he can hear no;3 arcing,from,from time to time ,this news leaves me at a lose end .Any idea's?

[jameslxdt]

swap the coil packs arround and see if the misfire follows the movement

[kal]

will try -jameslxdt let you know what the results are ?

[kal]

Tried swapping coil packs ,but still the same ,but in this warm spell fault has not accured ,for a few days now ??

[teamster1975]

I know I'm stating the obvious but have you tried changing the lead and plug?

[kal]

yes new plugs and plug caps,starting to think that maybe new coil pack has same fault as my old one .Maybe a manufacture weakness.? going to give her a good servis on the weekend ,using mobil 1 10 / 40 semi sinthetic,a new filter etc.

[teamster1975]

Very strange
Be interesting to see if the fault re-occurs when the weather gets damp again

[kal]

Hi well the weather got damp again!
And yes it happened again ,this got me thinking ,cold & wet conditions have adverse effects on electrical components and the flow of current.
Like most people i get into my car and turn the key straight away,so i changed the way i go about this .I now start my 406 this way-get in -turn ignition on-dash lights up-then i wait,until the ecu does it system check,and the petrol gauge rises, then i start her up !!
The results are this i've not had a single problem with her since,and yes i did try the old way and she went down again .So i've got a petrol 406 who thinks she's a diesil so what i can live with that ,all in the name of trouble free motoring. posting.php?mode=reply&f=1&t=4907#