2000 GT L67 swap dies on highway

[TheDarkAngel]

Really looking for help on this one. I have a 2000 GP GT, with an L67 swapped in, GT harness, tuned computer from intense, stock everything else except headers and intake. The car only dies out of town at highway speeds. Haven't gotten it to die in town, or anything like that. When it dies, it immediately cuts, doesn't sputter, just cuts out. Also only runs 91 octane. Never has anything less.

New in the last 6 months:
Crank and Cam sensors from BWD
New MAF
New fuel filter
New platinum plugs from Autolite (AP606)

things tested:
Fuel pressure is 45 psi at startup
ignition module and coils are good
wires are good
TPS was switched to another car with a known good one, performed the same, so it checks out, IAC is also good.

Suggestions are welcome.

 

[QUICKSILVER462]

Can you can get a scanner and hook it up so while you are driving you can data log what happens when it cuts off? Something intermittent like that is hard to narrow down without data.

 

[jimzssei]

My Bonneville did this - new ignition switch cured that ailment.