Unfortunately there likely isnt one... and even if you can get a temporary fix, you will still be needing to change those old caps if you want the machine to last. Apple used some cheap, nasty caps in some machines in that era, and as explained before, electrolytic caps have a finite life regardless of rating or quality. The original caps have likely well exceeded their rated lifetime in a lot of cases (many caps are rated to only 1000-2000hrs of use before failure... If a computer is used for 6 hours each day, every day for a year, then that equates to just shy of 2200hrs over the course of that year. That isnt even an unreasonable scenario in an office environment. Even with less intense use, say in a private home, it would not be unreasonable to say that the caps reach their projected end of life in say 5 years from the date of manufacture... the IIci is now 23 years old and running the original caps which are now almost guaranteed to be approaching or well past their rated hour life.
Even if the caps look fine, theres a good chance they arent or wont be for long... Uniserver some time ago put up a post where he took a couple of semi-functional logic boards and removed all the caps and tested them to prove this point that old electrolytics arent to be trusted even if they look fine. The caps looked externally ok, but some were no longer of the correct specification and some were either open circuit or short. And well, in spec or not, if they havent leaked yet, they will eventually and they can rot chips, traces and the board itself.
Whilst it might seem tempting to try and find an easy solution to a flakey machine, it's not worth taking the shortcuts... at worst you will borrow some time before your computer starts decomposing, at best, you will chase your tail and get nowhere. You really should replace all your caps, and its likely that many issues will disappear if further damage hasnt already occurred.