Our company's '07 PT(which was just in the shop last month to have the TIPM replaced 
) now has another problem.
One of our guys drove it to a customer's last week & when he tried to start it, it would only crank but not fire. We had it towed to a shop who checked it out, but said everything was OK. He picked it up the next day & drove it back to town without problem. It sat a couple days at our office & when he tried to start it again, it was the same thing - crank but no fire.
I checked & we're not getting any fuel pressure at the test port, and I don't hear the pump turning on(either from inside the car, or with an ear on the filler neck).
Any ideas where the fuel pump relay is located on this car? I don't see any instructions/diagrams about the fuses or relays.
Given my limited experience working on newer Chrysler products, I have my doubts that it's an actual pump/relay problem, and almost expect to find melted wires in the harness somewhere...
My Jeep had big time fuel pump problems, so I wouldn't be so sure.
Any check engine lights ?
There are a plethora of things that could cause your problem.
No, no codes/lights. Just cranks until the battery drains.
I looked under the rear seat to see about getting to the fuel pump wiring to test for voltage, but it looks like you have to pull the carpet out, which looks like I'd need to pull all the trim panels first.
I've fought enough crazy problems like this on other cars to realize it could also be something completely unrelated, like a TPS, coolant temp-sensor, etc. sending a bad signal to the ECU & preventing it from turning on the pump. 
I think only the crank position sensor could cause these symptoms, if the fuel pump fuse is ok. No CPS signal = no FP
FP fuse can go if the O2 heater wiring is shorting out...it's the same circuit.
I had similiar issues with a (couple) Neons. CPS both times. I haven't run into the blown fuse problem, but others have.
Does the CEL come on with the ignition in the "on" position? (IE: just before starting?) If not, that suggests the ECU isn't getting power and/or is fried. (one time problem on a neon)
there really arent any chryslerco products Ive ever really been interested in after the death of the Omni, so Im going back to the ignore thread...
Which fuse controls the fuel pump? I've looked in the manual, but nothing there references the pump. I checked codes again, but nothing is showing.
The CEL is on when in the "on" position.
I FOUND THE PROBLEM!!!! It begins with "PT Crui" and ends in "ser". 
