My '98 Expedition (5.4l, 4X4) has started a new problem on starting the engine. The key must be turned on, then immediately off, then back on to start the truck. If it is started with only one turn-on, ALL the warning lights flash and the truck runs very rough, to the point of almost dying. Starting the truck with two "turn-ons", it runs just fine with no lights flashing and everything working normally. Any ideas what may be causing this? I suspect some sort of fault in the computer module on the truck, but I am just guessing. Any similar experience you may have had and a solution to the glitch will be appreciated! Thanks.

 

It might be a good to confirm that the ign switch on the lower column is making good contact when first turned on.
Many of the circuits operate a such a low voltage any water intrusion at the PCM (computer) plugs could possibly be causing the problem. Check them all for any moisture /corrosion.

 

Thanks, Hanky. That will be a great place to start looking for the problem. I guess the ignition switch could be wearing out - the truck is 18 years old! It just seems odd that it always works fine on the second switch turn on. It never takes more than that!