Ongoing Saga with '03 LS V8 HELP! Failsafe Mode

I've had my '03 Lincoln LS 3.9 v8 at a ford dealership for two weeks and the dealership has no clue how to fix my vehicle.

In park I can rev my car normally and the engine runs smooth.. everything feels fine. As soon as I put it into drive and press the accelerator and go above 2,000 rpms the motor cuts out and goes into FAILSAFE MODE and starts shaking. If I stay below 2k RPMS I can usually putt around without it dying, but if I accelerate AT ALL it immediately loses power.

The dealership told me the codes suggested my throttle body was bad so I replaced that...didnt do anything.

Next they told me it must be the PCM. Replaced that today...just got a call that it didn't fix anything.

They now have no idea what it could be. I've told them for the past week that if a coil was bad (likely #4) it could cause RF intereference and that may be the problem but they claim they stress tested the coils and none failed so that I must be wrong.

What in the world should I do now? They still have my car and claim they will start troubleshooting all over again tomorrow. I don't think these guys have a clue.

I don't know why I am replying to this. Replace all the coils and all the plugs. It doesn't cost anywhere near as much as the parts you've thrown at it so far. I had zero doubt that replacing the PCM wasn't going to fix it, but I was/am tried of fighting with Daniel on this and other topics.

Here's a more active forum for you to post in if you want more opinions on it.
http://www.lincolnvscadillac.com/forumdisplay.php?f=7

LOL - BS RF interference - Lets throw more money on COP's & plugs!

If there's any evidence of a rust residue on COP cylinder #4 rubber boot, or spark plug, it's water causing single misfires. Single misfires on one cylinder isn't going to trigger a Limp/failsafe mode.

FYI - The silicone spark plug wires were designed to suppress noise. yes old copper spark plug wires would transmit noise that could actually heard on the radio.

If the LS mechanic felt the Throttle body, or PCM was bad, I said ''they should of been bench tested'', not replaced at the customers expense.

If the fuel pump test was done right and the jet pump(drivers side) is working, my money is on the drive-by-wire system.

Also see AF Similar Thread www.automotiveforums.com/vbulletin/showthread.php?t=1082132 (http://www.automotiveforums.com/vbulletin/showthread.php?t=1082132)

The dealership knows whats going on, they are in the business to sell new cars.