1998 Mercury Sable

After driving for 30+ minutes and shutting off car, it won’t start again until waiting 15 minutes for engine to cool. New battery, alternator & spark plugs/cables recently installed. Is there some kind of sensor overheating preventing car from starting again right away?

These kind problems are usually due to a problem in the ignition area. You need to check and see if spark is getting to the plugs while the trouble is occuring. There could be a fuel delivery problem also. If the ignition is working then I would check things related to the fuel system, like the fuel pump relay.

Thanks for your reply. Ignition is fine. Would fuel pump relay tend to not work only when engine is hot? Only time problem occurs is after driving at least half hour, shutting car off & trying to restart a few minutes later when engine is still hot. Car starts every time in morning going to work & after work when car has sat all day.
Thanks

You say, “Ignition is fine”. Do you mean that you know that the ignition is fine when the engine doesn’t start? Are you testing the ignition (spark) during the no-start periods?
The next major suspect area is fuel (fuel delivery, and fuel injection). To see if a lack of fuel, into the cylinders, is the problems, spray Starting Fluid into the intake when the engine doesn’t start. Results?