Cm870 running like it out of fuel???

[DVT873]

Ran into this on a while back ISC CM554. Looking at an ESN I have for an ISX 870 I see a very similar looking lift/transfer pump.
  Pump with Screen.pdf (Size: 290.6 KB / Downloads: 250). You have to dismantle the pump to see the screen. On the ISC this pump runs for 12 to 15 seconds at startup to move fuel from the tank to the engine then shuts off. Another pump downstream then gets restricted by the crap on the screen. That in turn starved the CAPS pump and killed it. The CAPS pumps did not like being starved for fuel. We used this gauge to see what was happening. Have to get on the right port on top. Simpler to just take the pump apart. Ours was in a pusher motor home under the bed and a real PIA to get at. The test port was easily reached so we started there. had about 12 Hg of restriction once engine was running.

Looking in Quickserve on the ESN I have 79189652 I see some variations of this but they all involve little screens.

At some point Cummins also ran fuel thru a plate the ECM was mounted to. For ECM cooling. Never saw it myself but have heard of those plugging up also. Restriction test is useful if you figure out the right test point.