I had a similar problem last week with my sentra. My car wouldn't start..The starter sounded good, everything was ok. the fuel pump..filters..everything was ok. Sometimes my car would start..sometimes it wouldn't. I had my tita's husband check my car. he checked it thoroughly n found that the distributor cap was all messed up. one of the distributors was cracked. we got that replaced n everything is fine now. We were going to take it to our mechanic.. who i dont trust fully (actually i dont trust any mechanic haha). good thing we didnt, because you never know what ELSE he'll "need" to replace. There's my 2 centavos.

U should tell those car alarm ppl to shove their alarm up their *ss. You don't fix an engine problem by upgrading your alarm. it's like trying to fix your TV by upgrading your microwave. its stupid.