My 2003 E150 idles perfect, revs perfect. Put it in drive and start off slowly, pretty well. Push the gas down and the engine pings very loudly and does not want to shift. It loses power.

I had a 1995 E-150 with a 5.0 that did the same thing. i spent alot of money at variuos shops, including dealerships. Found out from a co- worker that the 5.0 is bad about carbon build-up on top of the pistons. The carbon on the piston heats up and ignites the air and fuel in the cylinder before the spark plug has a chance to, causing the pre-ignition (pinging sound). My fix was a $6.00 bottle of Sea-Foam fuel additive in every other tank of gas until the pining stopped. Now I put Sea-Foam in 3 or 4 times a year, and have no problem. Sea-Foam is available at most major auto parts, and farm implement stores.Hope this helps !!!! S.Cox, Evansville IN