94 lesaber stalls while driving,,sometimes spedo jumps severaltime before it stalls,it dosent matter how fast or how long i drive ..fuel pressure ok ..new coilpacks new filter plugs n wires...i think the pumps ok too..

Fuel pump intermittent, check for fuel pressure before dropping the tank to renew pump.
Otherwise check electrical connection at battery, and make sure you do not have an open circuit.
Loss of connectivity could cause this issue, failed fuel pump sometimes work, but are not reliable.
You should see 30-45 psi at fuel rail, and the regulator should bump pressure 5 psi when reving the motor. Higher pressure indicates failed regulator.

indicates misfiring
possible fuel pressure loss or blocked exhaust from bad cat converter
run the fault codes to view reports

Thats where i would start more than likely its over do for change anyway.Then check your fuel pressure no matter if its a 6 cylinder or 8 cylinder it should be 44-54 psi with key on engine off.If not within specs replace pump.HOPE THIS HELPS!!

Usually, a map sensor and an idle control sensor can cause the rpms to jump. I had a bad map sensor and it did this. It also would die every now and then. Check your fuel pressure and make sure it is correct. It may be a fuel issue. If your check engine light is on, get it scanned at an auto part store. This may be your best bet. If not, I would look into the sensors. If you have a question, let me know. I am here to help you.

ok here we go, hook up a feul pressure guage that can be read from inside the car, and check fuel pressure while driving, if the pressure stays fairly constant then the best bet is to hook up a real time scanner with snapshot capabilities ( like snap on or bdm pro) and take it for a drive again, ti could be a sensor reading out of range but not enough to set a code

Check fuel pressure,fuel pump maybe on the way out.

i have a 1994 mercury grand marques and all of a sudden the blinkers, tail lights, and brake lights stopped working?

Check fuses and relays!

First thing to check is the fuel filter. It is likely getting clogged and starving the engine for fuel under heavy load.

First off, I'm a great believer in the simple solution. If jumping the relay works, then replace the relay.

As far as a relationship between fuel pump operation and oil pressure, coincidence of operation.

If the new relay fails you, I'll need some more info:

• Fuel Injected? If you turn the key on (not to start) do you hear the fuel pump come on for a sec then shut off?
• Hard to start when hot, cold, doesn't matter
• When it does start, does it idle ok? erratically? High? Won't stay running? Dies immediately?
  
• Does it blow smoke? Black? Blue? White?
• When driving, does it lack power? Stumble? Stall?

Hope it's the relay

Mike