I couple of weeks ago, I couldn't start my Explorer; AAA started it by holding the pedal down while starting, it started. I had the fuel filter replaced, along with the fuel pump relay. Right now it idle fine and is not experiencing any loss of power. The only thing is that when it is cold, I have a hard time starting the engine. Once it starts, it's fine. I took it back to the shop where I had the filter and relay changed, and they can't fine anything wrong. I brought an ohmmeter to check the resistance on the intake air temp (IAT) sensor and the engine coolant temp sensor, but what else should I look for? Plug and wires only have ~ 23,000 miles on them. Also, at one point gas was leaking from the expansion tank onto the spare tire, but has since stopped. Could this be related to the hard start when cold problem?