1992 Jeep Wrangler Engine won't start!

Hey Fellows, Hope Your Christmas and New Year kicked off on the right foot. Speaking of right foot, I've got this jeep wrangler that I have been struggling with to fix. Spark plugs and wires just replaced last year. With it's age and lengthened cranking requirement for normal starting, I first checked resistance on the coil and it was not in limits. Replaced the coil and ran great for about a month. One day the engine started cutting off/on. Did the self diagnosis and got the code for internal ground on alternator, replaced it. Ran for about ten minutes and started cutting out, but would start and run. Local shop said to replace the crank speed sensor, replaced it and started once couple minutes, but never again. Codes now show 33-35-55. I can't find the 35? With it's age, I really don't want to spend a fortune on diagnostic research! What would be your best recommendation?
Thanks, Jeff