i wouldnt go with a new carb just yet. i had the same problem in my 85 with a 22r. it would drive and run fine most of the time but once in a while it would just die. i couldnt figure it out, i was getting fuel and spark but i would not stay running. it ended up being a relay on the side of the fuse block where the connection was curroded. my advice is start it and start wiggling som wires, even the ones under ur dash on ur steering colum, if it dies then its a loose connection.
hope that helps,
anthony
