Inste 7.5 won't run cylinder cut out test

[Poptest]

Hello DK.....please, need some advise.

I'm working on an ISM-CM570 with ESN 34957024. Engine misfires and smokes a lot when loaded.

Insite 7.5 did not see any faults. I tried to do a cylinder cut out test to determine which injector was bad. Insite was able to do a cut out in cylinder 1. When I attempted to cut cyl 2, Insite displayed a message that it would not allow the test to proceed.

Please advise what's causing Insite to discontinue the cylinder cut out test wnen no injector faults were detected.

Thanks in advance.

[pbateman]

what is the message poptest?

[Poptest]

I was not able to write it down. Insite needs to be hooked up to the truck.

As I recall, the text stated that Insite detected a problem in the system and would not allow the test to proceed.

I will hook up on Monday.

[pbateman]

Poptest if you dont have this issue with hooking to any other truck. I would have to say the issue is in the ECM I would make sure there are no dents or dings in the cover of the ecm casing.also by looking at the esn # it looks to be a a 98 model? But I would check the ecm because it sounds like a issue there.

[jctech]

If there are any injector faults then Insite wil not run the test, also make sure that you run on 6 before cutting out the next cylinder, in older versions you could jump straight from 1 - 2 - 3 etc, and you could cut out several cylinders that way if not carefull.

[Poptest]

Poptest if you dont have this issue with hooking to any other truck. I would have to say the issue is in the ECM I would make sure there are no dents or dings in the cover of the ecm casing.also by looking at the esn # it looks to be a a 98 model? But I would check the ecm because it sounds like a issue there.

Hello pbateman......I've never experienced this situation before. Truck is a 99 model. Btw, I pullud off the harness to the oil pressure sensor and it logged a fault.

I hope it's not the ECM. I'll do more tests tomorrow.

[Poptest]

If there are any injector faults then Insite wil not run the test, also make sure that you run on 6 before cutting out the next cylinder, in older versions you could jump straight from 1 - 2 - 3 etc, and you could cut out several cylinders that way if not carefull.

Hi jctech.......ECM does not detect any injector fault, but engine has an audible and consistent cylinder misfire.

Is it possible that the ECM detects an injector/s fault but is unable to display the fault?

[mondao]

Mr. Poptest
you can test, test accelerator based cutout, maybe to work
you must not forget to put the Engine Fan in the "ON" position for continuous operation
this test is good

[jctech]

Hi jctech.......ECM does not detect any injector fault, but engine has an audible and consistent cylinder misfire.

Is it possible that the ECM detects an injector/s fault but is unable to display the fault?

You can verify fault display by unplugging an injector, if you cannot run the test with Insite, just do it manually by unplugging individual injectors.
Did you have the oil pressure sensor unplugged while trying to do the single cylinder cutout?

[mathura]

Hi jctech.......ECM does not detect any injector fault, but engine has an audible and consistent cylinder misfire.

Is it possible that the ECM detects an injector/s fault but is unable to display the fault?

DO AS JC SUGGESTED UNPLUG ONE INJECTOR AT A TIME TO IDENTIFY THE ONE WITH THE PROBELM.
However after locating the cylinder that is missing use a LED or test lamp to verify if you are getting power to the injector, once you have power then it could be an injector issue or worst case a cylinder issue.

[Poptest]

You can verify fault display by unplugging an injector, if you cannot run the test with Insite, just do it manually by unplugging individual injectors.
Did you have the oil pressure sensor unplugged while trying to do the single cylinder cutout?

Oil pressure sensor was hooked up when I did the cylinder cutout test. I unplugged in order to check if the ECM could detect/display faults.....which it did.

[Poptest]

DO AS JC SUGGESTED UNPLUG ONE INJECTOR AT A TIME TO IDENTIFY THE ONE WITH THE PROBELM.
However after locating the cylinder that is missing use a LED or test lamp to verify if you are getting power to the injector, once you have power then it could be an injector issue or worst case a cylinder issue.

I tried your suggestion mathure. But when I removed the valve cover, 3 injectors had broken plunger return springs. Injectors have now been pulled down for checking and/or replacement. Could it be possible that the ECM sees no injector faults as the problem is mechanical.....not electronic.

I will feedback DK regarding cylinder cutout as soon as injectors have been put back on.

[jctech]

I tried your suggestion mathure. But when I removed the valve cover, 3 injectors had broken plunger return springs. Injectors have now been pulled down for checking and/or replacement. Could it be possible that the ECM sees no injector faults as the problem is mechanical.....not electronic.

I will feedback DK regarding cylinder cutout as soon as injectors have been put back on.

It could be that when you cut out number 1 cylinder, along with the 3 that had broken springs, the RPM dropped below idle speed, the cutout test will not run if engine speed is below idle speed.

[Poptest]

ISM is now okay after putting in Recon injectors. Cylinder cutout test is also working this time.

Here's what I've observed:
1) An electronic injector with mechanical problems like a broken plunger return spring will cause the engine to misfire but may not log an injector fault.
2) As jctech stated, cylinder cutout test will not proceed if engine idle rpm is too low

Thank you for helping me out.

[jctech]

ISM is now okay after putting in Recon injectors. Cylinder cutout test is also working this time.

Here's what I've observed:
1) An electronic injector with mechanical problems like a broken plunger return spring will cause the engine to misfire but may not log an injector fault.
2) As jctech stated, cylinder cutout test will not proceed if engine idle rpm is too low

Thank you for helping me out.

The ECM only monitors the electric circuit from the ECM to the injector solenoid and the return, and will only log a fault if it observes an issue in the electric circuit.
Insite does not monitor any "mechanical" components, except for cam-crank relative position ( ISX/QSX cylinder power imbalance).

Remember, underneath the sensors and actuators is a "normal" diesel engine that still suffers from the same problems that they always have.

[renesis]

thanks for sharing the valuable information poptest.
we usually encounter smoke issues w/o any injector faults, and injector cut-off test usually does not exhibit any signs.
replacing the injectors solved the problem.