1997 Grand Marquis problems starting

Hello all,

We have an 1997 Mercury Grand Marquis. It isn’t driven very much – only about 25,000 miles total. Lately it has been having problems when we try to start it. Sometimes it starts right up, and sometimes it needs a few tries. When it fails, we can hear the engine turning over, but don’t get to ignition.

We drive this car a couple of times a month. Is it possible this issue is related to the infrequent use?

Could this be something more serious? What do we even ask the mechanic to look at?

Thanks a lot! Any feedback is highly appreciated.

How long has the gas been in there? Could it be sludged up? Techron and Sea Foam are good cleaners that you add to the gas tank.

infrequent use…=…old gas !
been there …done that.
1979 Chevy pickup in my driveway now.
Put Staybil in the tanks …TWO years ago. ( last I can remember ) today it will start right up if the battery is up to the task.

I’ve been through that years ago with this truck and old gas was the single factor of its driveability issues.

Most people only think of using fuel stabilizer in their…uh-hem…’‘stored’’ fuel like cans of gas for their mowers, atv, boats, snowmobiles, etc…completely forgetting just how long the rare drivers have had their gas in those tanks.

Staybil will NOT make bad gas good again.
You put it in with the new gas that you intend to be there for a while.

My bet is on bad gas too.
Because this car is used so little I’d plan on filling up with enough gas to take this months trips with plus a little to park it with, and use “stable”. I wouldn’t fill it and park it with more than 1/4 tank so you can dilute the bad gas if needed.


How long since it’s had a basic tune up with spark plugs, etc?

Hey guys,
Thank you so much for your replies! I didn’t realize that cartalk does not notify me when somebody replies to my post, hence the long silence. I am going to try to change the fuel and maybe do the tune up.
Many thanks! :slight_smile:

The hard starting might be caused by a faulty anti-drain back valve in the fuel pump assembly.

How this valve works is, when the fuel pump stops running the valve holds what is called residual fuel pressure in the fuel system. The valve then allows the residual fuel pressure to slowly bleed down to zero over 15-30 minutes. But the valve is suppose to retain a column of fuel in the fuel system so that when the fuel pump operates again the proper fuel pressure is immediately developed.

If the valve allows the column of fuel to drain back into the gas tank, it takes the fuel pump longer to refill the fuel system and develop the proper fuel pressure. Thereby making it difficult to get the engine to start.

To determine if this is what’s causing the problem, the next time the engine doesn’t want to start, turn the ignition switch off. Turn the ignition switch on so the dash lights come on for two seconds and then turn the ignition switch off. Repeat this a half dozen times and then try starting the engine. If the engine starts immediately the problem is with the anti-drain back valve in the fuel pump.


I’d guess some kind of fuel problem also. A fuel pressure test would be where I’d start. Test the fuel pressure at idle, and also verify it holds within spec after the engine is shut off. If that looked ok, before I dug further into the fuel system, I’d do a spark and compression test.