Just an update on where i am with the Cinq after i tried (and failed haha) to sort it in time for SICD.
It was "finished" 2 days before the event but the overfuelling issue i have been having when it gets hot, where at idle, it gave the odd pop and splutter, meaning emissions were crap was still there, so knowing it would fail, i didn't put it in for the test.
Been working on the assumption that it was a "simple" problem with a sensor, injectors etc but everything externally i checked was having little or no impact, so the only thing i could do was dig deeper.
Ran a compression test and immediately found the start of a problem. Whilst the results weren't especially clear cut, the compression was lower than it should have been, so that settled it, head off time.
So removed the head and found something immediately, the head gasket, albeit new, was failing in between cylinders 1 and 2, and techincally had failed in between 3 and 4 given the lightest carbon smearing. Basically regardless of what i found from here on in, the stripdown was a good call because it has saved me a breakdown. Took my feeler gauges to the head and ran a few measurements, head was out of tolerance, so it needed to be sent off for skim.
Still wasn't convinced it was the cause of the most obvious issue though, so packed up the head and brought it home to strip down. Valves need removed for these heads to be skimmed so i thought i'd run a quick hydro test on them, And..... Bingo! most of them were leaking. This means things were getting in and out when they shouldn't, so Map sensor was getting thrown off reding a bit of compression from the cylinders reaching the inlet so is/was dumping fuel in, combustion process was a mess in general, hence the popping at hot idle. Worst cylinder going on the state of the plugs also had by far the leakiest valves (all of them were leaking, the inlets were both gushing), so there's an issue found.
Sent of head for a skim, got it back yesterday and have spent about 10 hours all in cleaning up and lapping all the valves. Refitted, ran the same test as before and whilst not perfect, was a lot better and most were now fully sealed. Took the remaining leakers out, redid them, refitted, re-tested them and all passed. So hopefully that's that now.
It's pretty much ready to be rebuilt, with fresh (quality, genuine Fiat) gaskets, also putting on another new timing belt (Gates Powergrip) because A, it's my favoured make of belt, and B) the amount of times that old contitech belt has been touched, on, off, re-tensioned etc i didn't feel i could "trust" it, could well have been contaminated and failed early, so good practice to just fit a new belt whilst it's all apart.