Running rich/PC3

[Endless]

So she was running rough. Filters lines, tank cleaned. Came good. Off I rode to get her blue slipped, she started running on what felt like 3 cylinders. Had waited a couple of weeks for the mechanic to be available, was only a couple of kms down the road, so carried on. Turned right out of an intersection, she decided mid turn to run on all 4, power spun the new rear rubber and down we went. Towed to shop, and couple damaged bits replaced and blue slipped. What they have said about the misfiring; injectors cleaned and fresh plugs resolved it, however old plugs are black ie running rich. They think it's the PC3 and suggest removing it, rather than spend a ton of cash on dyno tuning. It has Yoshi cams and exhaust so not inclined to do that. Thoughts? Can the PC3 all of a sudden cause this? Its been running beautifully for years, never missed a beat. Any other avenues before I think about a dyno?

[Eric GSX1400K3]

Check all the FI inputs, i.e IAT, IAP, vac lines, CPS, CKS etc  and thr ht lines from thr coil packs to the plug covers

[grog]

Not sure if bike same, guessing yes. Cars with faulty map sensor run very rich.Diaphragm damaged causes it, often punctured by inlet backfire in early days due to fuelling set very lean. Electric plug resistance will check fine, its at idle but need vacuum applied to test over its full range.Swap ap to map to see if any difference or even run and remove plug from sensor to see. Lots of Suzuki use same sensor, Boulevard etc. Just my thoughts🤷T250 has post on this 2022,MAP Sensor heading.

[Hooli]

Not sure if bike same, guessing yes. Cars with faulty map sensor run very rich.Diaphragm damaged causes it, often punctured by inlet backfire in early days due to fuelling set very lean. Electric plug resistance will check fine, its at idle but need vacuum applied to test over its full range.Swap ap to map to see if any difference or even run and remove plug from sensor to see. Lots of Suzuki use same sensor, Boulevard etc. Just my thoughts🤷T250 has post on this 2022,MAP Sensor heading.

That could also make sense as to how it 'recovered' too Grog, 14s only use the MAP sensor at low revs/throttle & above a certain point revert to calculating with just TPS & revs.

I'd also check the oil temp sensor for a sane output (there's chart of values in the workshop manual), the two bikes I've known run very rich when they went high resistance were terrible at low speed but ran ok when revved up & given a decent amount of throttle.

[Endless]

MAP sensor makes good sense, will start there. Its still in shop so may even get them to check it. Oil temp sensor was damaged when laid down, so has a new one now.

[Hooli]

Oil temp sensor was damaged when laid down, so has a new one now.

How?
It's the one in the middle of the block behind the barrels, difficult to access to due to the Y-shaped external oil feed pipes.

[Endless]

Oop.. mixed my oil temp and oil pressure units up! 

[Hooli]

Easy to do as the sensor below the ignition cover on the RH side of the engine is the fan switch that works on oil temp so some people call that an oil temp sensor.

BTW the connector for the oil temp sensor is halfway up the RH side of the air box B/W & B wires as I recall. So easy to stick an Ohm meter on. The ones I've seen fail were showing over 1,000 kOhm rather than 100 at near freezing point hence the bike being very rich.