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+--- Thread: 4727 code (/showthread.php?tid=8323)
4727 code - Shawdog257 - 07-13-2022
Hello I have a code 4727 pop up. Injector metering rail 1 pressure data valid but above normal operating range. I think I got some bad fuel over in Texas so I replaced water separator filter and primary fuel filter. Cleaned davco housing good. Replace fuel rail check valve and fuel rail pressure sensor. No one in my area can seem to figure out the problem and I’m getting tired of just throwing parts at it. Any help would be appreciated. Cummins isx 2350 built 9-2014
RE: 4727 code - JimT - 07-13-2022
did you try logging in to Cummins Quickserve (free account for owners with up to 5 ESN's), look up the code and follow the associated troubleshooting instructions? Off the top of my head, for an over pressure code I think the possibilities are the fuel rail pressure relief valve or the fuel pump (actually I want to say the bypass valve in the pump head, but I could have the name wrong). My money would be on the pump head, but thats just a guess from a guy on the internet reading a few sentences.
Like I started out saying, look up the fault and troubleshooting information and go through the steps laid out to properly test and diagnose the issue.
RE: 4727 code - Rawze - 07-14-2022
- WILL IT pass a rail leak-down test?. Excessive pressure in the fuel rail from an injector allowing combustion pressures to back-feed and over-pressurize it... or simply excessive bleed-by from the pressure relief valve or an injector into the return fuel drain-lines can also cause this fault.
- I.E.> A rail leak down test to see if the rail holds pressure on its own. It cannot leak more then 4,000 PSI in one minute during the test. It if does, then something needs to be replaced. Capping the lines/injectors, etc. up to 3 at a time is how someone finds the issue instead of guessing like ignorant fools, wasting moneys.
ref: http://rawze.com/forums/showthread.php?tid=7915&pid=69262#pid69262
- Has anyone replaced the guts of the fuel pump in the last 400k miles (or 8,200 hours)?. if not then it is due for this any ways.