Car cranks but wants to start when i release the key but wont run

Frustrating ain't it? That one kicked my *** for a while.
Yes, make sure the brown and dark blue wire coming out of the bulkhead are in good shape. Remove the factory vinyl bundling tape and have a good look. They both have a welded splice that can be problematic. Also make sure you have a good ground to the ECU. Most people suggest running an extra ground wire to one of the case screws.