Misfiring Problems
Ignition Leads
Misfiring, with the accompanying rough running, power loss and even stalling, is much less common in the 4.0/4.6 than in the Classic. When it does occur, the prime suspects would be the ignition leads as on any vehicle. Peter Vorwerk of Switzerland had these symptoms on his 1996 4.6SE. After inspecting all the air-intake system and the throttle-position sensor he checked also the camshaft-sensor but didn't find anything strange. Noticing a "clickering" sound, he switched off the light in his garage and could see sparks flying around ignition-lead #2. The solution was a simple replacement with a new lead set. Update 2006: After another two years and 100,000 km, the same symptoms recurred and were cured by another change in leads.
Note: For some reason, 1999-2002 models with the Bosch ignition system are particularly prone to ignition lead failures.
I found this article that might help
Pascal
