Rawze.com: Rawze's ISX Technical Discussion and more
CM870 issues - Printable Version

+- Rawze.com: Rawze's ISX Technical Discussion and more (http://rawze.com/forums)
+-- Forum: Big Truck Technical Discussion... (/forumdisplay.php?fid=1)
+--- Forum: ISX Related Help (/forumdisplay.php?fid=68)
+--- Thread: CM870 issues (/showthread.php?tid=7754)



CM870 issues - Luckyjayb - 10-05-2021

{continuation of this thread... http://rawze.com/forums/showthread.php?tid=7747&pid=67943#pid67943 }

Well got the cylinder imbalance code and the test showed that the metering and timing solenoid were bad for the front bank. Ran overhead and did leak down test on injectors and they passed. The new solenoids did not fix the issue. Have swapped them around and nothing doing. Any ideas or thoughts?


RE: CM870 issues - Rawze - 10-05-2021

Will it run on one cylinder at a time like mentioned here?...
http://rawze.com/forums/showthread.php?tid=7747&pid=67948#pid67948

if it is not in the fuel system then ...

Have you put new crank and cam position sensors on it?. Anyone verified that the tone wheel on the crank does not have any play in it?

Anyone put the wedges in the cams to see if one has slipped?

Maybe remove the rocker shafts. pressurize the intake and then the exhaust manifolds up @ 20-psi ... and do a pressure leak test to see if your loosing compression due to valve seat seepage in a cylinder or 2?.

Anyone pull the injectors and looked to see if there is any scoring on the liner walls on a cylinder?.. could be a broken ring too.


RE: CM870 issues - Luckyjayb - 10-06-2021

(10-05-2021 )Rawze Wrote:  Will it run on one cylinder at a time like mentioned here?...
http://rawze.com/forums/showthread.php?tid=7747&pid=67948#pid67948

if it is not in the fuel system then ...

Have you put new crank and cam position sensors on it?. Anyone verified that the tone wheel on the crank does not have any play in it?

Anyone put the wedges in the cams to see if one has slipped?

Maybe remove the rocker shafts. pressurize the intake and then the exhaust manifolds up @ 20-psi ... and do a pressure leak test to see if your loosing compression due to valve seat seepage in a cylinder or 2?.

Anyone pull the injectors and looked to see if there is any scoring on the liner walls on a cylinder?.. could be a broken ring too.

Thanks Rawze. Will do those today!


RE: CM870 issues - Rawze - 10-06-2021

Might want to also check to ensure an engine brake rocker is not acting up. Sometimes they will cause one to run funky too if it is internally leaky and becoming partially active when it should not be.


RE: CM870 issues - Luckyjayb - 10-07-2021

(10-06-2021 )Rawze Wrote:  Might want to also check to ensure an engine brake rocker is not acting up. Sometimes they will cause one to run funky too if it is internally leaky and becoming partially active when it should not be.

thanks brother . turns out it was #2 and #3 injector. went ahead and replaced all 6. gonna rerun the overhead in the morning and adjust everything including jakes.