Mercury Grand Marquis 1989 V8 5.0 liter.
This is my second car, with all the snow here I have been using my 4WD for the last six weeks. Yesterday I cleared the remaining snow off the car and drove it a car length along the drive. Today I tried to start the Mercury, it turns over as normal but will not start ? I am wondering if water/snow has seeped into the fuel tank through the fuel cap door ? I had left the snow on the Marquis as I knew I would not need it in the winter. I will try to start the car tonight to see if I can see spark tracking in the engine compartment. I plan to fit a spare spark plug to an ignition lead to make sure there is a spark at the cylinder. Is there anything else I can do in day light.

thank you in advance

Perform tests in the link below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-11.html#post2123675

The problem may be the Ignition Control Module (ICM), AutoZone Part No. F121, $37.99. I recommend replacing this problematic component every 120,000 miles or 10 years, whichever comes first. Run through the tests and keep this in mind. Easy job to replace the ICM.