CCM Posted April 10, 2018 Share Posted April 10, 2018 I always recieve some good info here so i need help again. I'm working on a "09" Mack CXU613 (MP7) A few months ago we replaced all 6 injectors and not long after that we had to replace 2 due to fuel leaking from the bodies. All was working fine but came back with mid 128/psid 47/ fmi 0 and soot level codes. Checked regen system,found tee check valve at A/T fuel inj faulty. Replaced the check valve and all was good again. Returned again with same codes. Tried running regen and would not build temp. Removed dpf and sent to be cleaned. Reaseambled and ran regen. Still not temp. Have fault traced with G/D. Replaced egr valve. checked diff sensor,tubes,vgt lever,boost leaks,fuel pressure to A/T fuel doser and made sure it wasn't plugged. During regen the exh temps are (inlet 739) (after cat 969-978) (outlet 877-904) It goes back to idle and soot level reads the same and only code active is for soot level. I'm heading towards faulty DOC but who want to spend 5k on a guess? Any ideas? Quote Link to comment Share on other sites More sharing options...
turckster Posted April 11, 2018 Share Posted April 11, 2018 Have you tried multiple regens to see if the soot level would drop? The regen temps, at least to me, look good for a 2007 emission engine. How does the dpf diff. psi look during the regen? Was the 7th inj. cleaned and if so did you reset the adaptive factor for it? I would think if there was an issue with the DOC the inlet temp would be off and other temps as well. For example, if the DOC is face plugged the outlet temp usually passes the after cat temp. Quote Link to comment Share on other sites More sharing options...
Mackpro Posted April 11, 2018 Share Posted April 11, 2018 What is the soot ratio before and after the last regen? Those temps sound good. Quote Link to comment Share on other sites More sharing options...
CCM Posted April 11, 2018 Author Share Posted April 11, 2018 We had the filters cleaned and reset the soot level and reset back to 13% and after the first failed regen it jumped to 140%. We have tried to reset the soot level and won't reset. We have performed several regen's and soot level never drops. The diff pressure is at 0.27 to 0.29 psi. I have previously replaced the 7th inj due to an open circuit and have even removed it and cleaned it to be sure. The adaptive factor was reset. After the regen ends no other codes appear. Thanks for the response. Quote Link to comment Share on other sites More sharing options...
Mackpro Posted April 11, 2018 Share Posted April 11, 2018 I think you have to do a crystal sub regen to get soot to drop on some of the trucks. Quote Link to comment Share on other sites More sharing options...
Mackpro Posted April 11, 2018 Share Posted April 11, 2018 (edited) There is a bulletin on soot ratio stuck on 140% and it is do a crystal sublimation regen and soot ratio will drop Edited April 11, 2018 by Mackpro Quote Link to comment Share on other sites More sharing options...
CCM Posted April 12, 2018 Author Share Posted April 12, 2018 Can you run a crystal sublimation test even if the truck doesn't have DEF? Quote Link to comment Share on other sites More sharing options...
Mackpro Posted April 12, 2018 Share Posted April 12, 2018 Your correct , you can't on a non SCR truck. I think we had to update the dash cluster software onthe older ones. Let me check my notes in the morning Quote Link to comment Share on other sites More sharing options...
CCM Posted April 12, 2018 Author Share Posted April 12, 2018 Thanks Mackpro. I appreciate any help Quote Link to comment Share on other sites More sharing options...
CCM Posted April 26, 2018 Author Share Posted April 26, 2018 The customer had me on hold with this unit and now want's to continue with diag. Has anyone come up with any ideas with what could be the issue. Now for some reason I am unable to even reset the soot level. I've even checked for any ecu updates. Head scratcher!! Quote Link to comment Share on other sites More sharing options...
fjh Posted April 27, 2018 Share Posted April 27, 2018 Bro I got to ask has this truck been having any starting issues? We have had it where the cups are starting to loose seal and it causes the unit to never finish a regen for what ever reason ! once the cups were repaired life was good! just an observation! Quote Link to comment Share on other sites More sharing options...
Mackpro Posted April 28, 2018 Share Posted April 28, 2018 Did you flow test the 7th injector? When testing it with tech tool it should "chirp" and pulse/mist fuel. Not a constant stream of fuel Quote Link to comment Share on other sites More sharing options...
OJ Avery Posted May 3, 2018 Share Posted May 3, 2018 The 07 emission mp7 we usually see higher temps than that. 2010 emissions those temps are good. I'd say its not getting fuel to the 7th inj or the 7th injector itself. Quote Link to comment Share on other sites More sharing options...
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