Which engine do you have; single or dual cam? If it's the single cam engine, remove the cam sprocket and check the dowel pin to see if it's sheared off. If it is, that will let the sprocket turn a little on the camshaft. That retards the cam timing, and that is picked up by the cam sensor on the driver's side of the engine. The late timing looks the same to the Engine Computer as a jumped timing belt. At the equivalent of one tooth off the Check Engine light will come on and the code will be "cam and crank sync". At two teeth off the computer will shut the engine down to protect the valves. At three teeth off the open valves will be hit by the pistons.
The first one of these I ran into behaved exactly the same way as what you're describing. If you monitor the output of the automatic shutdown (ASD) relay during cranking, you are likely to see it's not staying on steady. The voltage at the coil pack, alternator field, or any injector will be turning on and off randomly.
Wednesday, December 5th, 2012 AT 9:48 PM