The engine will not start until fuel pressure is up to specs. It should hold pressure for many days, but in case it drops a little, the fuel pump runs for two seconds every time you turn the ignition switch to "Run". It doesn't run again until the engine computer sees engine rotation, (cranking or running).
With high mileage, you could have injectors or a check valve in the fuel pump that are leaking and allowing fuel pressure to drop. That two-second burst from the pump at "Run" might not be long enough to get the pressure up to where the engine will run. During cranking, the pump runs again, and when pressure is high enough, the engine starts.
This is nothing more than an inconvenience. If you want to verify this is the problem, turn the ignition switch to "run" for a few seconds, then off for five seconds, without cranking the engine. Do this once or twice more before cranking the engine. That will insure fuel pressure is up. If it starts faster, dropping fuel pressure is the problem.
Leaking injectors will allow raw fuel to run into the engine oil. This dilutes the oil and it looses its ability to lubricate. If you do most of your driving on the highway, the fuel will burn off. Lots of short trips could result in sludge in the oil from the hydrocarbons. Regular oil changes prevents that from happening.
In addition to injectors, the pressure can leak down through the pressure regulator or the pump check valve. Both of these are harmless because they drain fuel back into the tank. The result is the same; long crank time. You will have to decide how important this issue is. I'd forget about it. I did with my van.
Monday, March 30th, 2009 AT 1:02 AM