Fixing balky front shifting I've got a Campagnolo Chorus 2x9 drivetrain on my bike. Lately I've found that shifting to the big ring is very difficult: The only way to get it to shift at all is to make a simultaneous front and rear shift going little>big and big>little; I assume that this introduces slack into the chain to make the shift easier. This isn't always successful, and when it is, I wind up overshifting (which is easy enough to correct, happily).

It hasn't always been like this. Not sure where to begin diagnosing the problem.
This problem developing over time starting from it working well implies a cable gone slack (not really probable with old left Ergos because they usually have cable pull to spare) or derailer pivots that have gotten too sloppy to shove the chain with the right level of assertion. If the front derailer got shoved out of position or bent due to chain jam or other trauma this could also result. Errors in FD position or limit screw position could also cause this.

Grab the tail end of the FD cage and wiggle it firmly to see how its doing on slop. It should be negligible. Check for any tweaks of the cage or broken bits. If it looks good then go through and adjust all aspects of the FD - position, limit screws, and cable tension, in that order.

A severely worn chain or worn ramps/pins could degrade shifting enough that you get this issue, but aren't typically the root cause.