Here's the story: Towing my 5000lb trailer on May Long Weekend, I have 1 hole in my '97 4.6 die. Cause: Intake valve in #8 was pulled halfway inside out. Obvious signs of overheating in #8 hole only. I had engine rebuilt, drove truck for one week, engine develops LOUD ticking sound. Engine shop investigates, finds pistons fried, rebuilds again. I pick up truck, make it 30 km, engine "powers down" and stalls. Take truck back, rip on owner of engine shop. He takes truck out, brings it back sounding like a 7.3 powerstroke.
Here's what we know:

-Piston skirts are scratched to hell (after every failure)
-MAF has just been replaced (after 1st rebuild)
-during one diagnosis, timing was seen advanced to 70 degrees (yes, 70)
-We suspect ignition module or other "black box"
-Their scanners detect no faults in any system on my truck

This is a reputable engine shop that has done many DOHC 4.6 Mustangs, so my truck should be a cakewalk.

The shop guy has heard of a TSB from Ford on drivability complaints regarding pinging where Ford replaced the computer (and not just on warranty vehicles). Perhaps this means something?

Any help would be great. Oh, and after 2 rebulds (and a third failure), my block is too shredded to rebuild again. Time for a short block.

 

Sounds like a bad computer. I had the opposite problem on my mom's 1990 Olds. It was lacking power, so I had my buddy who has the $3,000 Snap-On scanner watch it run. The scanner was showing that the computer was retarding the timing 10deg. even at an idle. It was showing input from the knock sensor, even when I unplugged it. I replaced the ECM and it has ran great every since.
Jimmy

PS, it never threw a code either.