I ditched the shortys and had the Pacesetter LTs and Y pipe put on. Before that the car never shut itself off. So far it's done it once in the driveway, although it started right back up, and once while I was driving it. (Not good) The second time it took about 10 trys before it fired back up. It seemed like the longer I waited in between trys the more it wanted to start but didn't. Here's the strange part. I got out of the car (pissed off) to have a smoke, looked down at the door for the gas cap and figure lets check and make sure it clicks. It does, but I un-screw it to double check and a boat load off pressure comes out. (The car does have almost a full tank though). I get back in and it starts up after about 2 seconds of cranking.
So what do you guys think? Some sort of vapor lock? When it shuts off, it does it clean, no sputter no hesitation.
Im going to wrap the collector, Y pipe, and gas lines with some heat shield, but I would like to hear what you gents think about this. TIA

 

The fuel system is pressurized. The pressure there is normal, if its not there you will trip an SES light. I think it was just a coincidence that it started back up after you opened the cap.

It sounds to me like you have 1 of 2 problems. Either your loosing fuel or ignition. I noticed you have and MSD. I would start there.

I had an almost identical problem and I was chasing a ghost for a few weeks with mine. It would sometimes just shut off in the staging lanes. Sometimes it would restart, and other times it wouldnt be so easy. Several cranks and nothing but if it sat a while it would start right up. On ocasion I would loose ignition half way thru a run. And when it went out it would just shut off just like you pulled the key. Turned out to be my MSD6AL. I bypassed it and the problem went away. I have the MSD off the car but I just havent had time to send it back for repairs.

IMO, it sounds like an ignition problem.

 

Brian, I'll try bypassing the MSD, but it's strange that the car did it right after the LT install.
Anyone out there ever have to shield the fuel lines from there headers? Can a FI car even get vapor lock?

 

I guess its possible to get VL but highly unlikely. The pump is in the back and pushes the fuel thru the system. Unless the headers are routed under your tank I would highly doubt it.

And this happening just after the header install is probably just another coincidence.

If the MSD proves to not be the problem then you need to check for any loose connections. Make sure all your wiring and connectors are secure. Its very hard to t/shoot because by the time you set up to check for something it starts and everything is cool. I'll bet its the MSD but if you bypass it and the problem persists you need to set up to check for spark and fuel next time it happens.