Fmi 157 spn 18

[Hallmanhauling]

Hey guys I got a code on my truck for low fuel rail pressure. I’ve cleared it out and tried to make it come back up to see when it is happening. When I get on the interstate and do full throttle is when the code comes back up. I’ve replicated it twice already. I had an empty trailer. I replaced the high pressure fuel pump about 3 months ago and the rail sensor. I am at a loss right now as where to go from here. I don’t want to keep running the truck cause it won’t pull a hill for nothing when that code is on. Any help is appreciated.

[marek4792]

looks like you got the "559" code of engine destructing doom, did you change the tappets and plungers when you replaced the pump? That code usually means one of those things are/ or have failed!!! You could also have a big fuel leak somewhere or a bad pressure check valve or something if the pump, tappets, plungers, or head is all new. Definitely do not drive it anymore until you know for sure the pump hasn't gernaded!!

[Hallmanhauling]

Yeah when I changed the high pressure pump I put all new tappets and everything. The old one had Metal tappets as well. So in guessing they changed out the ceramic one when They found out they were having so many problems.

[Hallmanhauling]

I filled up my truck and drove about 100 miles before the code popped up the first time. Then I changed the filters to eliminate them as being the problem.

[Rawze]

see if it will pass a leak-down test.

[marek4792]

what year and model is your engine? demandated? could be a couple of things since you seem to have eliminated the biggest and most costly culprit.
could be any of these things if you have insite you can do a fuel rail pressure test to make sure you don't have a leaking injector, or pressure relief valve or sticking fuel pump actuator, or even a fuel line that isn't tightened enough which sounds most likely..

[Hallmanhauling]

Unfortunately I don’t have the on-site software to be able to do the test. I’ve been looking around for the software but haven’t been able to get it yet.

[Hallmanhauling]

(08-09-2020 )marek4792 Wrote:  what year and model is your engine? demandated? could be a couple of things since you seem to have eliminated the biggest and most costly culprit.
could be any of these things if you have insite you can do a fuel rail pressure test to make sure you don't have a leaking injector, or pressure relief valve or sticking fuel pump actuator, or even a fuel line that isn't tightened enough which sounds most likely..

It is a 2013 Freightliner. Cm 2250 isx 15. I’m gonna have to bite the bullet and take it to Cummins in the morning.

[JimT]

Where are you? maybe someone else nearby would be willing to hook up and perform the test?