Before investing in a new computer, check a few more things. My YJ had no spark and I thought it was a computer also. I would start by checking the fuel pump yourself. To do this, simply turn the key to the accessory position and have someone listen for the pump to prime from the gas tank. If it makes a sound, the pump is functioning. Next,check for spark from the coil. For this, pull the lead wire from your coil and just place it close to the engine block. If you get a weak or no so park, it could be a bad coil. This what my issue was. Another thing to check is the sensor that goes into your distributor. You need to pull your distributor to access this part, and if you do, make sure you pay careful attention to the positioning of the dist. If you try these troubleshooting techniques and it still will not start up, you should be able to order a new computer from a vendor like Quadratec. Good luck.
Jeff
Quick edit, have ou checked for any error codes by turning the ignition on and off a couple of times and counting the flashes?
