2000 Ford E-Series Van • V8 2WD Automatic • 124,678 miles

My engine has been pinging and looses power and starts breaking down after 50 mph for the last 6 months. It some days it runs perfect and the next it runs as I described. I've been to 4 shops and they cant find out what is wrong, its getting very frustrating, can you help!
January 17, 2011.

I would try rigging up a fuel pressure gauge that you can tape to the windshield and drive it so you can see what the fuel pressure is doing when this happens.

Jan 17, 2011.