Full crank, Almost Starts, then dies

My mom has been driving my liberty and had issues two weeks ago with the starter where the car wouldn't start, new starter, good to go. Two weeks later she goes to leave in the morning and it won't start. Full crank sputtered then died, then would just keep cranking.
I immediately figured fuel pump. Check all the fuses, swapped out relays, heard a him, had gas at the rail. Sprayed starting fluid in the throttle body and it would start and run fine, then sputter out and die. So I replaced the pump. Now evety attempt, it starts, then dies. Gas pedal/throttle position changes nothing. No codes, no prior symptoms.
I'm going to check duel pressure now, as I should've before(tester is at the shop, can't get it till monday) and grab my compression tester. I replaced the plugs about a month ago and although one of the coils could've probably been replaced, nothing seemed too out of the ordinary. Hot but not fouled. As they've seemed from day one with this thing. No discoloration of oil or loss of coolant..

Thought the worst thing wrong with my jeep was a leaky exhaust but now I'm not too positive. If all looks good elsewhere, I'm gunna drop my exhaust from behind the manifold and see if it starts and runs. But wanted to check here since 1 it's been forever since I posted here, and 2.. usually someone on here ends up having some needed insight

Do you have the SKIS red LED flashing at you or staying ON all the time....should light up with ignition turned on then should go out after a few seconds if SKIS is happy. Older KJs have an amber "key" icon instead of the LED.

If this LED flashes all the time the engine will fire up and run for a few seconds then die out. If the LED is ON all the time the engine will turn over but never fire.

Fuel filter OK?

Neither.
Haven't gotten my pressure gauge from work yet, but there's not really anything coming out of the Schrader valve. Perhaps I got a faulty pump but aren't delphi pumps the actual oe part? Will state that rather than a buzz, you can hear the fuel pump make two distinct clicking sounds when you turn the key to on. Not so much a humm or buzz

For fuel psi specs & further related info see this post:
http://www.jeepkj.com/forum/f196/03-liberty-sport-fuel-pump-35-40-psi-running-lean-61525/

Billwill said:

Do you have the SKIS red LED flashing at you or staying ON all the time....should light up with ignition turned on then should go out after a few seconds if SKIS is happy. Older KJs have an amber "key" icon instead of the LED.

If this LED flashes all the time the engine will fire up and run for a few seconds then die out. If the LED is ON all the time the engine will turn over but never fire.

Fuel filter OK?

Click to expand...

Theres neither a amber key icon or any flashing red lights, should there be?

GunnerSchenck said:

Theres neither a amber key icon or any flashing red lights, should there be?

Click to expand...

There definitely should be either an amber "key" icon on early KJs or a red LED on the LHS of the cluster on newer KJs.

When ignition is initially switched ON this light should come on for a few seconds then go out if the SKIS system is happy.

If you do not see this LED/icon come ON for a few seconds then do the cluster lamp/gauge exercise which turns all lamps ON/OFF and moves the gauges around. Do this by holding IN the Odometer trip button while turning the ignition ON.
The lamps will all light up and the gauges will move around...ends with the odometer display showing something like 1.141 which is the firmware level of the cluster.

This is not a diagnostic for the cluster but is useful to see if a previous owner/Dealer has removed any lamp or LED in the cluster to hide any problems!

Billwill said:

There definitely should be either an amber "key" icon on early KJs or a red LED on the LHS of the cluster on newer KJs.

Click to expand...

Only if you have the thick gray key,thin black key you will not have the factory alarm.

Well it's an 03 so probably an earlier model. We've had the jeep a long long time so I don't believe the led has been tampered with. Only time I've ever had an issues with the keys was when I drove it with my unchipped spare a few years back.
It runs through the cluster self check you mentioned.
*Edit* I just found the amber key icon, although I do have a thin black key and alarm..
The key icon only lights up when I run through the gauge self check thing. Not when starting or any other time at all.

Also, just double checked, there's definitely 0psi getting to the fuel rail. So it's not restricted, something is definitely cutting power or not getting any..

My 02 will do the exact same thing every time the battery cables get corroded or the battery is on its was out. Seems odd that there's enough juice to crank it over but not run the fuel pump, but it has done this 3 times over the years so now when it starts that I just go buy a battery and I'm back on the road. Mine does not have a chipped key and never has, not all of them do.

Battery is about 2 months old and had been holding steady voltage since this occurred 4 days ago and has been attempted to start alot of times and still cranking extremely hard with minimal voltage drop so.. I'm gunna go with its not the battery.

Might as well update as I go. 0psi at the fuel rail, continuity at both wires for the pump and both for the float sensor.. pulled the line off the pump and cranked it with a hose connected to the outlet. Nothing coming out at all, but the connector is getting power when the keys turned on.
Almost wanna go return the pump and try again lol

Update:
Good to go. Ended up being that the connector from the pump wasn't properly making connection with the top plate that goes on the tank and has the body sides connector plug into it. Realized this when putting power directly to the connector on top, no fuel was pushed out the outlet. So I took lines off, took the locking ring off, pulled the top plate up and pulled the connector underneath off.
When I put power to it, low and behold, fuel comes right out. So I forced the connector up into place and wonderpussed her there.
Wouldn't have expected the delphi pumps connection to be so odd, but I guess it could be blamed on the unit I was plugging it into. But the return line was much more difficult to install into the bottom than it shouldve been as well. Aftermarket sh*t, aftermarket fit... even though it's the oe part

All I know is she's good to go now (biggthumpup)