The short answer, is the low pressure fuel pump, is built into the CP3 high pressure pump. The CRD didn't come from the factory with a separate in-tank pump.
Mopar decided that because the low pressure priming pump "could" pull enough vacuum to draw the fuel from the tank and through the fuel filter without assistance, that they would save a few bucks per vehicle, by leaving it out. The result is, fuel lines designed for holding fuel pressure in, are now tasked with holding air out, and they do that quite poorly. The more load the engine is tasked with, the worse they do. Also, in cold weather, Fuel is thicker and requires more vacuum to move it.
It is quite common, especially during cold weather, that the CP3 actually pulls enough vacuum that it sucks air into the fuel lines through the filter head, through the push lock fittings back by the tank, and possibly through any loosely clamped connector.
You can temporarily bleed this air out, by pumping the hand plunger at the fuel filter head, and cracking open the bleeder on the opposite side of the filter head. You should have a short hose and container handy to catch the fuel that comes out with the air.
This is the reason for all the lift pump mod threads. There are various approaches from installing a Mopar Diesel unit from a Cummins Diesel pickup tank to firewall mounted units, but the colder your winters are, the more you should look to the in-tank solution. It is the only solution that, barring normal product wear and tear longevity, will completely eliminate all sources of air - in - fuel problems, period. If you don't have sub freezing winters, it's possible you could get away with a less expensive under-hood electronic pump. My life takes me to a pretty wide range of climate from sea level to high desert, so I chose the factory Carter unit from a 2006 Dodge 1 ton pickup tank, and did the wiring harness myself. Sasquatch Parts and IDParts both sell new in-tank pump and sender units. Sasquatch also makes a Plug-and-play wiring loom with floor weather grommet properly installed and located, and correctly wired connectors both inside and outside, if that's the way you choose.
If you are planning to keep your Jeep for a year or more, I absolutely believe this is one of the most important mods you can do to your CRD. Most of the potential driveability problems are averted, and it helps make your CP3.. a very expensive critical part, last longer.
Either way, the CRD comes with a fused relay circuit and timer already built in. They just didn't bother to put a pump in. Only the fuel level sending unit.
Sorry for the very long answer to a nice concise question. I hope it was understandable.