Years ago I removed the ECU (89661-2B290) from my '92 due to the CEL staying on. It was later that I found this due to a failed capacitor.
At the time I never considered repairing this and bought a replacement ECU from a forum member. It didn't help that my ECU looked like it was run over by a tank. .
It wasn't until I saw a FB post of someone in need of a replacement ECU (theirs was in the same condition) that I remembered mine and decided to pull it from the attic for repair. After some online searching and seeing that this is a common issue, naturally I assumed mine is a ticking time bomb so I figured it would be wise to have a back-up ready.
I pulled two capacitors, both were leaking electrolyte. One on both the top and bottom board.
I cleaned the electrolyte from the boards and placed an order for the replacements. I found the capacitors on ebay for very little. Just search "10uf 50v capacitors" (if it's the same caps obviously), I got a pack of ten for less than .40 cents each. http://www.ebay.com/itm/292182493462