For the past month, my Corolla (1991, 204,000 mi) has been exhibiting an annoying behavior. When the key is turned to start the car, there is often a pause or delay before the engine starts. During this pause, all of the dashboard lights come on as usual. There is no sound when the key is first turned or during the pause. At the end of the pause the engine starts normally. If the key is kept turned during the pause the car has never failed to eventually start.
The duration of the pause varies from a fraction of a second up to a few seconds and often does not occur at all. The pause almost always occurs on the first start of the day. After that it is difficult to discern if any pattern is present.
Can you think of any reasons this may be occurring? Thank you!