(05-25-2019 )MommaBurt Wrote:  On the smaller Cummins engines I know that you can unplug the fuel rail pressure sensor and the engine will stay running. It runs at max fuel pressure but doesn't shut off. I dont know if that's the same on the isx. That may get you somewhere else to work on it or charge the batteries.

(05-25-2019 )Ironsled Wrote:  Yes I can pulll it out easily but tapping it a few times and it does not return uppwards like it should . I’m assuming the check valve is bad in the head and that would explain why the system won’t pressure to spec . Am I wrong ? Can check valves be replace ? Or do I have to replace the whole assembly

(05-25-2019 )Slavic S Wrote:  

(05-25-2019 )Ironsled Wrote:  Yes I can pulll it out easily but tapping it a few times and it does not return uppwards like it should . I’m assuming the check valve is bad in the head and that would explain why the system won’t pressure to spec . Am I wrong ? Can check valves be replace ? Or do I have to replace the whole assembly

Was the pump head recently rebuilt? If yes , were tappets changed or only inspected? If they were only inspected and installed back in head using same crasher/washers, then You need new crasher/washers ( just to get going to where you need to get) . But a FULL head rebuild needs to be done asap. That is if previosly head rebuild was not done completely with new parts.

(05-25-2019 )Ironsled Wrote:  

(05-25-2019 )Slavic S Wrote:  

(05-25-2019 )Ironsled Wrote:  Yes I can pulll it out easily but tapping it a few times and it does not return uppwards like it should . I’m assuming the check valve is bad in the head and that would explain why the system won’t pressure to spec . Am I wrong ? Can check valves be replace ? Or do I have to replace the whole assembly

Was the pump head recently rebuilt? If yes , were tappets changed or only inspected? If they were only inspected and installed back in head using same crasher/washers, then You need new crasher/washers ( just to get going to where you need to get) . But a FULL head rebuild needs to be done asap. That is if previosly head rebuild was not done completely with new parts.

I bought the truck with 404,000 on it and have no record of it being done before nor after have I been in the shop for that . So no sir . Your talking about the crush washer part #4984382 ?

(05-25-2019 )Slavic S Wrote:  

(05-25-2019 )Ironsled Wrote:  

(05-25-2019 )Slavic S Wrote:  

(05-25-2019 )Ironsled Wrote:  Yes I can pulll it out easily but tapping it a few times and it does not return uppwards like it should . I’m assuming the check valve is bad in the head and that would explain why the system won’t pressure to spec . Am I wrong ? Can check valves be replace ? Or do I have to replace the whole assembly

Was the pump head recently rebuilt? If yes , were tappets changed or only inspected? If they were only inspected and installed back in head using same crasher/washers, then You need new crasher/washers ( just to get going to where you need to get) . But a FULL head rebuild needs to be done asap. That is if previosly head rebuild was not done completely with new parts.

I bought the truck with 404,000 on it and have no record of it being done before nor after have I been in the shop for that . So no sir . Your talking about the crush washer part #4984382 ?

Yes, that is how those crush washers look.
I had that problem of one of the plungers not wanting to come up on its own. Engine would start but soon after die due to fuel starvation. Only one plunger working apperently is not enough.
But again, thinking about it, maybe check valve somehow does not close... Either way, Insite would greatly help...

(05-25-2019 )Lonestar10 Wrote:  i do beleive most people who rebuild just buy it part by part washers/plungers/yada yada and just put all new parts in. i dont think cummins has an actual "kit" for the parts.