1994 Cadilac Sedan Deville 4.9 Liter

check your mass air flow sensor

Do you have normal fuel pressure when you first crank it ?

There are several things to check first. Are you getting fuel? (If you spray starting fluid in the throttle body does the vehicle start) (if it does you have a fuel delivery problem) If you take a spark plug wire off and crank the motor (put wire near metal to make a ground) does it spark? For bad spark I would check distributor/cam sensor or crank sensor>? These componenets will make no spark. Let me know what happens? I can give you more info once you check these things, but off the top of my head I can't just guess whats wrong without more info.

It is having a hard time reading your chip in your key. I have the same problem on my 99. You can get them replaced but there not cheap.

fuel pressure is probably bleeding off when it sets for a period. it probably is bleeding off into the return line if you see no leaks.turn the key on for 30 seconds then off before starting. if you dont like this then you can replace all of the fuel line o-rings in the system and pressure regulator/fuel rail assembly

you need to figure out if your missing spark at the plgs,or check fuel pressure at fuel rail,you'll need at least 55psi of fuel pressure,but if you have had no luck spraying the throttle body,your probably missing spark

Squirt starting fluid in intake and try to start if it starts and then dies you have a fuel delivery problem. Make sure you check the fuses for a blown fuse namely fuel pump or fuelpump relay. If it doesnt start after squirting starting fluid in the intake check for spark at the plug wires and coil.

replace fuel filter.check fuel pressure.

Fords have the reset switch option only. Relays are mounted on the firewall

sounds like a bad mass air flow sensor. this sensor is located on the duct that connects to where the air filter goes, it should have one or two wires coming from it. Unfortunitly they are rather expensive so you will want to have someone with a computer hook up to your car and tell you what the exact problem is before you just go and poke around replacing expensive parts that do not need to be replaced.