Caterpillar PMG3516C (XQ1475G) starts and Stalls Immediately 2

[Banji Isioye]

Good day all,

I have a Caterpillar gas engine PMG3516C that worked perfectly about 3 months ago. I have tried starting it since last week. It cranks, starts but stalls immediately after start-up without any error code on EMCP 4 display or the CAT ET. The stop seems to be an external stop it usually records on the AGC-4 display when you stop the engine normally but this time I am not the one initiating the stop. I have checked and inspected all settings, sensors and any thing that may be out of place. The actuator position command, the fuel metering valve, the turbocharger compressor bypass position all appear fine. Checked the threshold prtection settings and observed during crank and start-up, none of the readings are near the threshold values.

Please help with any ideas to resolve this issue. Thank you. I have attached a video of the start-up and shutdown behaviour.

 

[Banji Isioye]

I also observed the solenoid valve shuts immediately after start up and the fuel gauge pressure after the solenoid valve drops suddenly however the pressure before the solenoid valve remains constant as it should. It could be a protection setting but the problem is that it is not announcing so you cannot tell what to check.

I have attached the PSRPT

 

[enginesrus]

I am not familiar with those reports, but it to me looks like an over redundant confusing mess. It appears they need a scan tool similar to everyday automotive work, they are just more logical.
You said it was a Gas engine how come on the report diesel is mentioned? You need a tool that can check sensors and operate the various valves. A guess of mine with a start and stall would be a crank position sensor.
An intermittent signal can cause both lack of ignition and fuel.

 

[catserveng]

Since you are able to pull a status report, you should also be able to run a datalog file with CAT ET, if you are not sure how to setup the datalog then ask, can help walk you thru it. Didn't we have a similar discussion a while back?

You also need to "clean up" your logged codes, since you have pulled the status report and have a file copy, now clear the logged codes from all your ECM's from CAT ET.

You seem to be getting a lot of exhaust temp low codes, from not too many hours ago, have you investigated those issues?

You have a very old version of the software in your EMCP4.2 control, you need to update it to the current version for your panel, as there were known issues with some versions of the earlier software. Take a look at the logged codes for the EMCP, note that your top problem is an unexpected shutdown, along with a bunch of erratic engine speed issue (19 occurrences in about 24 engine hours), so based just on those two things when is the last time someone pulled, inspected and cleaned the magnetic speed pickups and reinstalled them to proper clearance?

You also have a bunch of other issues noted in a relatively short time span, such as "Fail to Auto Start" (typical with EMCP software issues if you are using auto start feature). Several overheat events, and numerous voltage and frequency events likely related to lower than expected engine speed. The phase sequence incorrect is most likely another indicator of a software issue, unless you ran the engine backwards, swapped voltage sensing or some other abnormal event to make that error show up multiple times.

Your video was unhelpful, a datalog would be best, if you try another video then pull up the engine data screen on the EMCP4 and capture it while the engine cranks and comes up to speed.

MikeL.

 

[Banji Isioye]

@enginesrus, it is a Caterpillar Electronic Technician, I have tried changing the settings from diesel generator to gas but I am unable to. I will try another ET the next time I am on site although I believe this setting doesn't stop the generator from running because we have 2 of the generators and the other one is running still with same settings. I have checked those sensors and the valves especially related to fuel system. They are responding as they should.
The timing/crankcase/speed sensor appears to be fine because while cranking all the ECMs (EMCP and AGC-4) displays the speed going up and coming down immediately after it starts and shut down. if the signal error is intermittent then the shutdown should be random however this is not, immediately the generator cranks and starts, the next 2 seconds is a shutdown.

 

[Banji Isioye]

Mikel,

Yes you have been helpful on these generators, you have provided some feedback before but that was a separate issue and it was for the second generator although same specification. The difficulty with logging the data is that the generator cranks, starts and shutdown immediately (2 seconds) without an error code displaying on the EMCP or AGC-4 on the CAT Switchgear panel but I can still log it anyways.

We have done so much troubleshooting on the generator and most of the event codes displayed happened while we doing that. The fail to start was when I shut off gas to confirm if we had fuel system issues.

The exhaust temp was never low, You mean Exhaust Temp Sensor: Current below normal? There are codes that pop up once you uninstall the sensors or connectors. We recently had to remove the whole exhaust pipes and bellows because of water ingress, I believe those codes came up during that process.

I am unable to get any update for EMCP but I have the flash file for the latest ECM software, I will try to update it when I return to site. I have in mind to just change the speed sensors, we changed the sensors for the other one so it will be best to do so for this.

 

[TugboatEng]

The cam position sensors on the Cats should be changed in pairs of you suspect there to be an issue with one. The engine will not run with a mismatched pair of sensors.

What is your power supply to the engine control module?

 

[Lou Scannon]

The details you have provided make me think that as far as the engine control is concerned, the shutdown (right after start) is normal and does not initiate any trouble codes. Maybe the "run" (as opposed to "start") output of the upper level (plant) control is not reaching the engine control. So as long as it is receiving a start signal, it is good to go, but whatever mode it is transitioning to after the start, is faulty (outside of the CAT control).
Just a guess. I do not know anything specific about this system.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[Banji Isioye]

@TugboatEng, the ECM used 12VDC to power the speed sensors. I do not think we have a problem with mismatched sensors as the engine was running fine before. I have not tested the output yet but while cranking I monitored speed display and they were fine. I will check and measure when I get back to site.

@Lou Scannon, I have thought about the run relay issue, will see if I can get a troubleshooting guide for that.

Thanks to you all. I will try all possible checks and troubleshooting.

 

[TugboatEng]

I was wondering about power for your ECM directly. A small interruption of power can shut everything down without logging any codes. This would also explain your inability to run a data logger during the event.

 

[Banji Isioye]

@TugboatEng, for this engine, the ECM controls everything regarding the start and stop, if it is losing power intermittently then the shutdown should occur randomly but this particular shutdown is fixed, once you start it, the next 2 seconds is a shutdown without a code on the EMCP. Moreover I have connected CAT Electronic Technician and monitored parameters related to the ECM, the parameters displayed the readings through out during start up and shutdown periods. Not sure that is the case but I will still observe.

 

[Lou Scannon]

Failing more sophisticated diagnostic techniques, if you have another working engine that you can take out of operation, you could try swapping suspect components between the good engine and the malfunctioning one.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[catserveng]

The G3516C has a single speed timing sensor that senses off the left bank cam gear, the engine ECM uses a 3-pin powered speed pickup. The EMCP4 can either take engine speed from the ECM over the data link or from a passive (2 pin) magnetic pickup. Both of the speed pickups sense off the flywheel ring gear. Based on the status report you attached the EMCP4 is getting engine speed from the data link.

The 3pin sensor for the ECM does have a history or problems at higher hours, several of the customers I know replace them annually or at overhaul (top ends and majors) to prevent nuisance problems. At a minimum make sure it is clean, remove from flywheel housing, clean and inspect, make sure it doesn't look like it made contact with the fluwheel, and reinstall install it per the service manual for correct clearence.

How are you starting the unit? Do you put the EMCP in AUTO and start at the AGC4 control panel? Have you tried just doing a MAN start from the EMCP4? If so does it act the same or different?

Hopefully you will setup a datalog, the CAT ET datalog function will usually find the issue with most engine and generator issues if properly setup.

Just setup the log for a timed attempt, I'd set it for about 20 minutes so you can capture multiple start attempts.
Set the rate at 240 times a minute.

I'd suggest using the following parameters to start,
From EMCP4,
IC contact input
Customer Stop input
E-Stop input
From Engine ECM,
Actual Eng Speed
Desired Eng Speed
Engine Run Status
Actual Ignition Timing
Fuel Actuator Position
Throttle Actuator Position
Bypass Actuator Position

Your engine ECM should have all these parameters available.

Ideally try a remote start with EMCP4 in AUTO first, and with same data log running retry to start in MANUAL from the EMCP4

Post you datalog when you get it.

MikeL.

 

[Banji Isioye]

@Lou Scannon, the issue with swapping is that one of the generators are already working perfectly., the client will not allow a swap.


@MikeL, thanks always for the support. I will carry out all these instructions and give feedback.

 

[Banji Isioye]

Hello,

I am on the field now. After carrying out ignition tests and speed tests on the engine, we found out that one of the cylinders was not firing at all. We carried out continuity test for the ignition harness of this particular cylinder and it passed. I know the ECM circuit driver are paired meaning one driver sends signal to two cylinders. Cylinder 9 and 7 are paired according to the SIS manual. Cylinder 9 is not firing at all while cylinder 7 is firing. The suspect now is the main ECM hardware. The ECMs are two- Primary and Secondary. My intention is to swap the primary for secondary since they are basically the same ECM but I need to reprogram the initial primary ECM to act as secondary while the initial secondary act as primary however I need the flash files to do that. I was able to get the flash file used for the primary ECM and successfully flashed the initial secondary ECM to act as primary but I do not have the flash file for the secondary ECM.
Please if you have access to Web SIS 2.0,kindly help with the flash file before I demobilize. I am trying to get the access but for now I cannot.

The details of the flash file required:
Software Part Number- 3227250-01 (The upgraded version if available will be appreciated) for Adem3(A3) ECM
ECM Part Number- 3482392-01
ECM Serial Number- 1952B060AL
G3500 ASM Software

 

[TugboatEng]

Can you not download the flash file off a known good ECM? You said you have access to multiple units.

 

[Banji Isioye]

I thought about that but how do you download the flash file off an ECM? I am not sure if it is possible with CAT ET

 

[TugboatEng]

I believe there is a replace ECM function in ET which starts by downloading the current flash file.

 

[Banji Isioye]

Yes but you can only download or copy a configuration from an ECM to another not the ECM software itself. I believe it works like every other software on your desktop with .exe extension. You cannot download the software to a file, the only way is to have the file extension to install.

 

[catserveng]

No, you cannot extract a flash from an ECM, you have to have the install file that is compatible with the currently installed file to be able to upgrade. Also in many cases you need a factory password to flash an ECM.

The ECM replacement function in CAT ET just provides a complete list of all settable parameters currently installed so if you do have to change an ECM or update it to a later configuration (such as a rerate) you don't have to go back thru the ECM settings and redo them manually.

MikeL.