1993 Mercury Grand Marque Won't Start


Monday Night the car ran fine. Big Rain. Tuesday it won’t start. I have added HEAT to the gas tank and purged some gas from the pressure port at the front of the engine. I have spark, I have good gas. Could I have a module that got wet and where would it be. I was looking at the EDiS8 module and wondered “HMMMM”?. The other thing that is going on is that my running light do not turn off ever when the key is removed and drains the battery. I thought at first I have bad headlamp switch so I took the dash apart and unplugged it, Lights still on. It seems weird that both things happened at the same time. Could the brain be bad and how do I check it after I find it?. P.S. The starter was replaced a month ago.


First a couple of questions. You say the “running light” stays on? Do you mean the Daytime Running Light (DLR)? If not what?

You say you have good gas and spark. How do you know? You have not said, but I am guessing that the car does not start. Does it never start or not start sometimes? What exactly happens when you try to start it? Details please. How old are the plugs and more important the plug wires? Why was the starter replaced last month and was that problem totally resolved? I there any anti-theft devices on your car?


The EDIS module controls the ignition coils. You said that there is spark. Here is the wiring diagram. Click on Fig 5 for the 4.6L engine. http://www.autozone.com/az/cds/en_us/0900823d/80/17/3d/a8/0900823d80173da8/repairInfoPages.htm
You don’t know if that fuel is going into the engine. Use a spray of Starter Fluid in the intake tube. Attempt an engine start. If it starts and runs a few seconds, and dies, you know the fuel injectors aren’t spraying. If it doesn’t run for a few seconds, recheck the spark.


Yes. The day time running lights are staying on. The ones on the front and also on the back of the car. I was actually able to ge the car started for a brief amount of time until I let off the starter, then it dies again. I am now suspecting the ignition switch is possibly bad.
I can hear the fuel pump come on when the key is turned to the on posistion, and there is a pressure test port on the top of the engine between the two fuel injector headers that I was able to bleed gas out of by pressing down on the needle valve (similar to a tire valve) with a small screwdriver when the key is in the on posistion.
The starter was replaced a month ago because it was bad. It appeared to be the original 1993 install. The starter issue is resolved (I believe).
Plug wires and Plugs are in need of replacement and that will be done very soon, but I don’t think that that would keep it from starting just out of the blue.


Will it stay running with a little throttle? If so, you need an Idle air control valve. I doubt that the lights and engine problem are related. They are different modules. Try asking at Crownvic.net. There are good people there too and they know this car well.