I'm having trouble starting my 98 XJ with 84K miles. When the enigne had been at rest for an extended period of time, it will refuse to start when I key to the start position the first time, but it will crank normally. If I key off and then key back to the start position, the enigne will crank and start right up. I've had trouble starting the truck for a while, but it has gotten worse in the last 2 weeks. In the last 4 weeks, I've installed an MSD6 box, MSD coil, and plugs. I added these parts as improvments not to repalce damaged or faulty components. The cap, rotor, and wires are all less than a year old. I've done fuel pressure test and at the first start of the day, when I key to the on position I'm getting about 5psi. When the engine is running, I'm getting about 48psi. When I key off, the pressure drops almost immediately to 20psi then continues to drop to 0 in about 5 minutes. I just ran a diagnostic using my scan tool and I got a P351 DTC, but the Check Engine Light is off. This forum has been extremely helpful in the past and I'm hoping to get some help figuring out what I need to do to get this fixed.