First lesson when you buy a Cadillac, always use OEM (AC Delco or Delphi) parts. Any others (aftermarket) brands are just cheap replacements. There is no such thing as a high performance fuel pump, the OEM pump was designed to have enough flow to maintain the engine running at 7000 RPM all day long (with the OEM injectors).
A long trip is always a good thing for the car (always), clean the pipes, valves, etc. In fact the worst thing for a char is short and frequent stops (like a pizza delivery car).
The beauty cover is the big plastic cover (silver in color) that sits on top of the engine (the one held with 4 plastic nuts with the text "Northstar 32 Valves V8" on the front edge (covers the top of the engine - intake manifold & fuel line).
The fuel sending unit (FSU) is always included with a new pump, you can buy separately a FSU but not just a fuel pump (I am talking OEM).
'98 and newer Sevilles do have a access panel on top of the fuel pump so you can access the fuel pump from the inside of the trunk, no need to drop the tank (that statement is available on '97 and older Sevilles and all Eldorados up to '02. This panel transforms the Fuel Pump job from a $900 - 4h job to a $350-$400 30 minutes job. Visit
kckranz's FSU Job album, he posted some EXCELLENT pictures with the fuel pump.
So check your pressure as I mentioned, Ranger is right you can only tell if you have or not pressure (not how much) but if you have seen a good car, knowing what kind of spray to expect you should be able to tell if the pressure is good or not. But first of all will tell you if you have pressure or not on the fuel line. Unfortunately I have no electrical diagram for your year so I can tell you witch fuse is what but here is what you can do with NO tools at all.
1. Make sure ALL fuses are OK. If a fuse is stuck try to wiggle along the long axis of the fuse. You should have a fuse extractor (looking like a short chubby tweezers) - at least my car came with one. Also not sure if ’99 has-it but my ’97 does have a sticker with the title of each fuse/relay (like FUEL PUMP, DRL, FOG, IGN, etc.).
2. Turn the key ON and go in the trunk, remove the liner (
see this picture) and put your ear against the panel, or better yet just remove the panel and listen if you hear the pump working). With the panel removed and the sky pass opened you should hear the pump from the driver’s seat (better ask a helper to turn the key while you are in the trunk near the pump listening).
3. If no hum then the pump is either burned or the fuse/relay is gone. If the fuse(s) are good then try swapping the fuel pump relay with another one (any relay with the same number of pins is good).
4. If you hear the hum then you go to the beauty cover and do the valve spray test. The gas should spray like crazy when pressing the valve nipple (shield the area and yourself with a rag). Remember though, the key should be ON when testing this. If it has enough pressure to spray hard enough to almost scare/impress you then the car should start, maybe will have the tendency to stumble while revving the engine (say every time you try to pass over 2000 RPM the engine will stumble (as if the gas limiter will kick in) or even the engine will die (any of these symptoms denote a low fuel line pressure). Also test for pressure after turning the key OFF. You should have pressure on the line for few seconds (until you drain-it from the valve). If no pressure after, the pump hold valve is gone so although the pump electrically is fine it pumps gas back into the tank.
Another lesson after this, never EVER run the car with low fuel in the tank. The fuel is the coolant agent for the pump, low fuel means pump runs hot. I’ve been for a while on this forum and almost every fuel pump thread starts with “I thought I was low on fuel”. I am always keeping my fuel tank above the half mark (but that’s just me I am to extreme) but at least keep the fuel always over 1/3, is not like you save any money, in the end you use the same amount of gas. I understand your fuel gauge was defective, but is such an inexpensive repair! Also in my experience once the fuel level sending unit is gone the fuel pump follows in about a year or so.
One more time, make sure electrical the pump is OK has no excuse not to run, then do the pressure test (if you hear the humm). Remember not to run low on gas next time and there is no such thing as performance aftermarket parts for Cadillac, OEM is the ONLY way to go, that discussion is for Hondas and other similar cars.
Re: Car won't start fuel problem 
