no power whatsoever!

[bent valves]

That is good news about the lift pump.

I just looked at my truck and saw how close to the lift pump that MAP sensor is, about 2 inches. I will guess when changing out the pump you may have hit the MAP sensor wiring. It is really awkward to reach that darn pump. You say you removed the sensor and it looked clean but what about the electrical connections? Jiggling the electrical connection may have caused in intermittent connection and set the P0238 code. By the way, I checked one of my Cummins manuals about that fault code and it says:

The MAP sensor is monitored with engine RPM above 400 but less than 3520 and battery voltage greater than 10.4 volts.

The fault code is set when the MAP sensor voltage is greater than 4.88 volts at start or with the engine running for 2.0 seconds.

This sensor measures manifold pressure and provides a signal to the ECM. The MAP sensor puts out a low voltage signal (0.5 to 1.8 volts) at idle when the manifold pressure is low. When the manifold pressure is high, and a higher voltage signal (3.9 to 4.8 volts) at deep throttle. The MAP receives a 5-volt supply from the ECM. This supply voltage may vary from 4.8 to 5.1 volts. The sensor ground is provided by the ECM.

Possible causes for this code:
Signal circuit open
Sensor open internally
Sensor ground circuit open
Sensor signal circuit shorted to supply voltage
Failed ECM (I hope it is not this one.)

Here is a photo of the MAP sensor and wiring to the ECM. About all you can do with a voltmeter is check between +5 volts and Ground on the wiring harness. The MAP sensor is a solid-state circuit (computer chip) and is difficult to measure. If you measure the 5-volts on the harness, I would just change out the sensor with new. I am assuming you have tried cleaning the electrical connections.

I have exceeded my photo quote. Oh well

__________________
Dave
1998 24Valve, BD dual turbo, Mach 4, Smarty, APB, ARP studs, Rickson 19.5s, DPP 4" SS, CON OFE.