I have been scratching my head with this one for a while and I'm now at a loss. It's a long story of trial and error so far but I will keep it short with relevant points.

A number of months ago I pulled into my garage with our 2002 S-Type Base. It would not start the next day. Determined it was a bad fuel pump. Replaced the fuel pump and sender assemblies and it ran well for a number of weeks and then the same thing happened, pulled into the garage and it would not start the next day. I don't remember why, but that day I had found myself arriving home with dangerously low fuel. So when it wouldn't start the next day, I figured I had simply made it home 'on fumes' and I was out of fuel. Added 4 gal of fuel to no avail. I don't have a fuel pressure tester but I then decided it was a bad pressure regulator as it would fire right up with starting fluid, I could hear the pump running to prime, yet I'd get only a dribble of fuel, if that, from the fuel pressure test port when I depressed the valve. Thinking the pressure regulator was probably not demanding fuel and having the pump turn on. Replaced the regulator, still no start.

My OBD scanner does not show any codes or other data. Checked fuses, all good. Fuel pump relays are good. I did get power on the pump connector pins but I tried hot wiring the pump anyhow to keep it in a run condition, still seemed to be no real pressure at the rail. Disconnecting the fuel line at the pump and turning the ignition on, the pump does pump fuel but the pressure seems pretty lackluster. I could easily retain the pressure at the end of my waste hose with my finger. I'm just trying to figure out what I can/should test/retest next. Should I go find a pressure tester? Possible I damaged the pump running it that low? The car as 250k+ so I didn't spring for a name brand pump. I've read a number of other posts that get into checking signals from the ECM but I'm not sure if or where a good place to start there is–having only a good multimeter and my OBD scanner. Given the nature of the onset of the no start, it does seem like either I damaged the pumps impeller or I have an electrical issue somewhere related to the ECM, maybe some sort of short that developed or something. Unfortunately, my rudimentary pressure testing methods don't prove much given my lack of knowledge on what to expect. My gut says the pump is toast but I'd like to get further verification before I buy another one and tackle that again as it seems it could still also be electrical related. Any advice would be greatly appreciated. Thanks!

 

Use a smart phone with the Torque app to connect the PCM via the OBD port with a Bluetooth interface to read fuel pressure.

With the ignition in the ON position prior to engaging the starter motor, there should be around 300 kPa (3 bar) pressure.

The CKP also sends a signal to the PCM to confirm the crankshaft is rotating. If the signal is not present, the PCM shuts off the fuel pump.

 

Sorry video where a guy was having a similar problem and replace the fuel pump and still ran like crap. So similar but not exactly the same. Brought the car to the shop and the shop emptied the tank and what they found was half a dozen of those little plastic sealing caps thingies that they put on the fuel system cleaning bottles under the cap. I guess they fell off the bottles and were in the tank blocking the fuel pick up on the fuel pump

 

Thanks for the replies guys. I ended up grabbing a pressure test gauge and pressure wouldn't even register, even directly at the fuel pump so I figured for sure my problem was definitely with something in that tank. Took the fuel pump out and I noticed one of the fuel lines (the smaller one) that crosses the tank to the other sender/pickup was loose. I wasn't sure if it was loose already or my tugging had popped it. Anyway, the locking ring in it seemed kind of cockeyed so I decided to fix and reconnect. Wouldn't you know it, the car fired right up! I guess it had come loose so the pump was simply pumping back in the tank and I only got a dribble at the rail due to the pressure differential.