Nissan: security system, nissan pathfinder, time ideas

Question
We have a 96 Nissan Pathfinder with 100,000 miles on it that just started having difficulty starting. It turns over but won't catch. The mechanic put in a new distributor and fuel injector, and has since tried every wire and relay and found nothing more wrong. He thinks the security system connected to the computer is going haywire and shutting down the computer that allows it to run. He's not sure what else to do. It starts sometimes and sometimes not. It also starts sometimes when we use the power lock to lock and then unlock the car, but not every time. Ideas?   Thanks - SC

Answer
Not to sound sarcastic here but you need to find a new mechanic. It takes three things for an engine to start!! Always remember this: AIR, GAS and SPARK. First you need to figure out which one is missing and then you have two thirds of the problem diagnosed. I can help you further when you tell me which one is missing. He owes you a refund for the distributor, fuel injector and any other time he has cost you. The alarm system kills the fuel pump only. If this guy read up on the system he would know this right away. Fact is most cars work like this.