help please, merlin!

i have a 2000 express van, 5.7l, tbi, 63,000 miles. replaced the fuel pump at 59k, do not think it is related to current problem. truck starts and runs approx 2 seconds, stalls. has 64 psi fuel pressure. has good spark. injectors shut off right after starting. behaves as though it has a security system problem discussed in the post about the tahoe. i do have a tech 2 but have not used it beyond airbag system programming and repair/diagnostics. is there something the scan tool will test in the securtiy system or to see why the injectors are shutting off? i am a well skilled tech in general but have not experienced anything of this type. thanks in advance.

Food for thought... are you losing ground or voltage to the injectors when they shut off? A lost voltage condition indicates a problem with ignition or switched 12 volts. If the ground is being lost, look for another signal to the ECM which controls the ground, such as signals from the module, distributor,etc. Ray

is your ignition switch operating in the run position?