348 Euro 348 Engine Troubles

Hi all - have been a longtime F Chat lurker, fairly new F Car owner. Earlier this year I picked up an early Euro 348tb (2.7) Non Cat, around 60k km.

We did a Major:
- Engine out belt service
- New cam shaft seals & cam cover gaskets
- New spark plugs
- Oil change

From this point the car was running pretty well, no misfires or power issues.

After a few weekends of spirited drives, maybe 1000km, I started to get to know the car and an understanding of what seemed to be baseline and what seemed to be out of ordinary.

Initial Observations: ~1500km
- high idle, never below 1k RPM, tended to float around 1.2/1.4k
- water temp would like to rise if idling for too long, around 100 celsius
- cold starts were okay, hot starts required at least 2 cycles (cranking once, wait a second, try again)
- would not rev past 6.5k RPM under any conditions

Eventually after a morning of spirited driving, and a lunch break, the car would barely start back up. When we got it going after a few cycles and patience, it started to misfire/cut power pretty aggressively around 2/3k rpm. I was able to limp home and eventually to the shop the next week - retrospectively I believe the car was running on only one bank at that time.

Fast forward a few months - we performed a fairly extensive overhaul of the controls around the engine to address the issues with power loss & hot starting issues:
- New spark plug wires, coils, & modules (2 were found to be out of range, all contacts were cleaned as well)
- Rebuilt flywheel - found that there was a leak at some point, gummed up the flywheel with grease and needed to be replaced
- Replaced battery - was not holding power well
- Replaced fuel pump (left), in tank rubber (a lot of rubber degradation & debris were found & cleaned out)

Current Observations: ~200 km of driving, over a few days, post shop
After all of this work, we were able to improve a bit - no more hot start issues, engine now revs to 7.5k RPM.
However:
- cold start requires 2 cycles
- high idle still present, with temps increasing if stationary for too long
- pressure coming from fuel tank (and some heat), can feel when unscrewing the filler cap - strange
- initially started small misfires around 3k RPM on highway, and has ultimately degraded to what seems to be 1 cylinder bank in operation (right bank) - essentially can limp the car around the block

At this point I'm looking to understand what else can be done to address any of the above issues - any advice/feedback is appreciated. The 348 is a great, underrated F car in my opinion, and I would like to get more miles on the car as soon as I can.

 

Additional note- both crank sensors were replaced as well.