Fiat Stilo 1.6 16v reg'd 29-01-2004
I have just got this car. It has a misfire all through the range but particularly noticeable on tickover. I removed the plugs and plug no 2 was a good colour, plugs 1 & 3 were black and plug 4 was oily. I exchanged plugs 2 & 4 and the good coloured plug that was now in 4 became oily. I exchanged the 2 & 4 HT coil/plug covers with no effect - no 4 will spark to the block with the engine running. There is no blue smoke from the exhaust and no obvious 'breathing' from the crankcase. The diagnostic shows 'no codes'.
I'm stuck!!!!

Sorry but despite what you've done so far, I would suspect coil failure as the No 1 suspect...

Thanks for that - it's just they're so b**** expensive, even on ebay.

Just to update....
I checked spark and everything was OK I also checked the valve gear and cams and all OK. On a pressure test 1, 2, & 3 were OK but 4 was zilch. I could hear pressure coming out of the oil filler so have concluded that the problem was either a hole in the piston or other such disaster. Obviously the cure is another engine which I have now fitted and all OK as far as that goes BUT>>>>>
The crankshaft sensor and its mopunting bracket were missing on the new engine. No problem, I have taken them off the old engine but how on earth do you set up the ignition timing? I bought one of those useless CD workshop manuals from ebay because Mr Haynes doesn't do a manual for the Stilo (would a Punto one be the same?) and there isn't a word on it about how to do ignition timing or even how many degrees of static advance I need.
Can anyone help please?
Colin

Well done with putting a new engine in. But you have some catching up to do with modern ignition systems theory

You don't set up the ignition timing like we did with older engines. If you've installed the crank/rpm sensor and left just a very small air gap between the sensor head and the serrated pick up ring then that's it, job done, and the ECU will work out from that where the crank and TDC is going to be. The ignition timing and fuel delivery is constantly monitored and altered by the ECU relying purely on the engine sensors, MAP, O2 sensors and cam sensor etc to tell it what is going on so there is no static ignition timing any more