A 98 EV can give fault codes, get the factory FI supplement manual for the codes ( on thisoldtractor.com ) there a red LED under the left side cover that blinks the codes, start or attempt to start it then turn off key but not all the way off to start the code flasher. The codes don’t cover everything but the crank, cam and temp sensors are included.
what does it do? Start and idle or not start at all and what does it do if not starting?
there is a fuel trim dial on the computer box, covered with a plug, if that were messed with it can cause a lot of bad behavior of the motor if you decide to tweak it only go half turn at a time and give it a 10 minute ride to let cpu adjust itself to the change.