Cadillac Repair: 1991 cadillac eldorado biarritz, cadillac eldorado, fuel pump relay

Question
Having some problems with the 1991 eldorado biarritz. It has 75,000 km. This is what it has been doing:
while driving at any speed, suddenly the electronic dash goes funny, km will turn into miles, gas will show 5 gallons when it actually is full, both odometers will stop, speed only shows 0, heater will stop. I turn the car off and restart and everything is ok. Just lately, starting the car, it wants to stall and does, but eventually starts again. Now it is in my driveway and won't start, doesn't even fire so I presume it is a computer problem. If you could help me with advice on these problems it would be greatly appreciated. I've taken it to a GM dealer, they are dumbfounded, do not know what it could be. thank you.
Kelly

Answer
EXACTLY what do you mean when you say it won't FIRE ?.

Are you NOT getting spark to the spark plugs or are you NOT getting any fuel pressure ?.

Fuel pump test:

1. Get yourself a helper.

2. remove the gas cap.

3. have one person listen in the gas tank at the gas cap opening.

4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.

5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.

6. Does it ?.


If you do NOT hear it run, in most cases the fault is the fuel pump relay or the fuel pump..



let me know.