Hi, I've been having a problem with my '93 300E for a couple of years now. 95% of the time it starts up perfectly. The other 5% is a mystery, there is no rhyme or reason to it. It will crank over but not start right away. It has happened after a 3 hour trip, a 5 minute trip or when its been sitting for hours. When it happens, sometimes it takes 3 or 4 cranks before it starts, sometimes its 20 minutes of trying it before it will start. On 2 occasions it did'nt start at all. I had it trailered to my mechanic's and both times it started right up and I drove it off the trailer. It also hesitates when accelerating. I'm hoping the two problems are related. The Mercedes dealership changed the feul pump relay, feul pumps, feul filter, spark plugs and wires. My mechanic changed the crank sensor, oxygen sensor and a (used) engine computer. Nothing has changed. He says the feul pump relay is getting power but the computer is not telling the relay to turn the feul pumps on. The wires between the computer and relay are fine. What else could it be? Sorry this was long and thank you for your help.