My van seems to have a longer than normal crank time before if finally starts. I’ve tried to cycle the key several times to pressure up the fuel system before engaging the starter…. same result. It starts the same whether the engine is cold or hot. Could this be a crank or cam position sensor issue? If so, how do I check it/them? The Check Engine light is not on.
Another diagnostic is to press the gas pedal a little while cranking. If that works, the cause could be the idle air control valve (blocked) or a dirty throttle body (choking off the air supply).
Other causes of a slow start are dirty fuel injectors (insufficient fuel flow) or worn spark plugs, as you already mentioned. Bad gas cannot be ruled out; fuel up at a top tier station.
Lastly, always listen for the fuel pump when you turn the key on. If you don’t hear it, the main FI relay could be flaky or the immobilizer is wrongly blocking fuel delivery.
Source: Dave