Quote:
Originally Posted by jacwjames
OK, I got a chance to look at my service manual and found the info on the posted fault code and found some other information on line. Attached is what I found.
My question is on the original lift pump. Although I bypassed the feed side of the pump I left the return side in tact. Does anyone know if there is any type of restriction on the return side that may have caused a problem.
Only other this may be the relief valve in the FASS pump itself. If it allowed higher pressure it could be the cause the problem. When the engine started to stumble the first thing I did was jump in the cab and look for any check engine lights and the fuel pressure gauge, the pressure was ~16psi as usual and not fluctuating.
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My understanding is the return line passes through the lift pump manifold, unencumbered.
Reading the pdf you linked and knowing the fuel flow sequence of the CAPS system, I would conclude your FASS pump cannot be responsible. Here's why:
The FASS pump/lift pump only supplies fuel to the mechanical fuel pump of the CAPS system. It is from the mechanical fuel pump that the fuel is pressurized into the accumulator where the sensor is located. The FASS pump is not involved.
Fuel from the accumulator is sent to the Injector Control Valve (ICV) and then to the fuel distributor. The ICV is also where fuel is sent back to the tank. The ICV is controlled by the ECM. Now, given that both the pressure sensor and ICV are electronic, there is always the possibility of bad connections. There was a Cummins recall/replacement for the connector to the CAPS pump due to vibrations and bad connections developing.
Linear Mode
