Lincoln Repair Questions? Ask a Mechanic for Answers ASAP
Usually, when an engine that was otherwise working fine won't start after being worked on, the cause can be traced to something that was left disconnected or damaged during that work.
However, if that's not the case with your Navigator, then we need to dig a little deeper into the issue. For example, you say there is fuel pressure; does that mean it's 35-45 psi Key On Engine Off? Also, other than no spark, are there any other conditions that may prevent the engine from starting? For example, is there injector pulse? Is engine compression more than 120 psi evenly across all cylinders?