Cadillac: Stalling out, pvc valve, cadillac sedan deville

Question
I have a 1991 Cadillac Sedan DeVille. I brought it from my cousin ($800.00)(about 2 months ago), after it had set up for over 4 Years. It ran good. drove it for about 3 weeks then it started to give me problems.

It began to loose gas mileage (from 19.8 to 7.9 mpg), at the same time it began to loose power going up grades. It ran fine on level ground and going down grades. Then it started to stall out on me. After letting it set for about 1 hour it started and ran for about 10 - 15 miles, then it would stall out again. It has been doing this for the past week. I used it only on short local trips. A friend told me to change the fuel filter that runs along the passenger side under the car.

It ran and got me to L.A. which is about 45 miles from where I live, then it stalled out again. Then this friend told me that there was a module under the distributor cap that when it heats up it will stall out. I changed the module, rotor, and the distributor cap. Now it won't start at all.

I have tried to us 'starting fluid' but that does not do any good (acts like it is not getting fire to the distributor).

It is getting fuel, I checked the fuel line. I changed the PVC Valve. I checked all the fuses in the two boxes under the hood. There seems to be fuses missing in the fuse box inside - under the dash. All the fuses that are there are good.

Please give me a little idea and some advice as to what is wrong.

Another friend of mine had the same year and model, his started doing the same thing, he sold his, and never found out what was wrong.

Thank You, for your help.

Answer
The first thing we want to do is check for computer CODES:

1. Ignition ON. Engine OFF.

2. Simultaneously push and hold the OFF and WARMER buttons until the whole display illuminates and then relaese the buttons.

3. Write down the ..E and .E.E and ..F and .F.F codes EXACTLY as they appear on they display and then you will see .7.0

4. Turn ignition OFF.



Now:

5. Ignition ON. Engine OFF.

6. Simultaneously push and hold the OFF and WARMER buttons until the whole display illuminates and then relaese the buttons.

7. as soon as you see the .7.0 push and hold the OFF and HI buttons until you see E.0.0 then push the OFF and LO buttons until you see F.0.0.

8. Turn OFF the ignition.


NOW: Repeat steps 1 thru 4 and let me know what codes reappear.