98 plymouth voyager won't start

I have a '98 plymouth voyager with a 3.3L. it has about 150,000 miles. It ran really well all of the time but did make intermitent noises from the passenger side of the motor…like the noise of an idler or something. It would make that noise for a couple days/weeks then go away for awhile. On day i pulled out of a parking space and went about 3 car lengths and it just shut down. It turns over fine, just no fire. I took it to the dealer and he said that there is 10 lbs of pressure in one cylinder. Fuel pressure is fine with no blow back. They said they couldn’t know more without going way into the engine…any thoughts?