N14 celect plus erratic idle

[Rawze]

Sounds to me like it could bad injectors, leaking into the cylinders?. When they do, it causes it to rev up a bit on its own, rpm to become unstable.

Watch the live fuel flow in Insite and see if it is going to 0 fueling when it revs up on its own. If it is, then it is a leaky injector giving it fuel when it is not supposed to.

It may or may not have been something done wrong when you worked on it but also...

-= N14 == Mostly there are only crappy injectors that have been remanned to death are running around out there for them. -= It would not surprise me if your reman injectors are leaky and causing issues. I have seen people go thru 2 dozen sometimes just to get a good set of 6.

That engine is no longer supported and the engine maker is no longer making new stock parts for them. -= One of the many reasons that I would never own one these days.

just some thoughts.