We have a 3406b 2ek peec motor that has been giving us Some intermittent issues that have become persistent. It started with cutting out occasionally, turned into dying and a crank no start condition then would be fine for a few thousand miles. We had it to the local international dealer twice early on and they didn't find anything. During a the crank no start with the rack position motor removed I could move the rack with a screw driver and it would fire up. I read there could be an issue with ecm power and ground and eliminated that by direct wiring 12v and ground from the battery. The last trip we made with the truck it died a few times and was low on power and blowing white smoke. It's making 5 psi boost at best and white smoke that burns your eyes. Leads me to believe it was a timing issue, after trying to diagnose it, it is showing code 44 (timing subsystem fault) not sure what exactly that means. I wasn't getting a feedback signal through the timing position sensor and thought I had found the issue. $650 sensor later it is now getting a signal through the sensor but it still smokes white and has low boost and low power. Fuel supply pressure was 55psi through the rpm range, turbo seals are not leaking. Sorry for the long winded post, any advice on how to check the advance unit on a peec pump or any other advice on where to go from here would be appreciated, thank you!
Going to need an engine serial number I bet.
Trying to remember But those had a plastic/nylon arm on the timing advance that would break. And there was a bulletin on it about wrong oil level {dip sticks were wrong on level}. It could cause cavitation oil pump sending bubbles through system once oil reached advance the bubbles would cause that arm to bounce and eventually break it. Had one years ago with that problem. But that was a long time ago.
Psst 2Ek. Bob
LOL…I read that twice and totally missed it.
Is the arm on the timing motor the one that would fail? I can see that is still intact unless there's something else that has an arm on it. I moved the control rod in and out that the timing motor controls and there is no difference in engine sound, seems to me if the timing advance unit was functioning, I would be able to hear a differnce in the motor.
Attached a bit of an explanation. The reference to Code 44 is on Page 8. The P-241 & P-242 tests mentioned are in a 2nd document that starts on Page 12. To do the diagnosis will require an ECAP Tool and I bet even most Cat dealers would struggle to find one of those today. Hopefully someone might be able to suggest an alternative.
Really surprised this engine wasn't converted to manual years ago.
Yeah. We had a bunch of them in gensets with a customer about 20 years ago. They were fine until you took them to more than about 2000ft ASL, of course the customer's job site was at an altitude three times that......... Eventually we came up with a method to fool the atmospheric pressure sensor and make it believe it was around sea level. From then on they ran somewhat OK. Always thought the PEEC system was a POS though. Strange I walked past one a couple of months ago as it was being removed from a local Home Depot store where it had been installed as an emergency generator. I imagine that was from new.
The VA hospital here has two for gensets.
Thank you for the diagnostic document. Ill try to get some testing done in the next couple of days and let you know if I find the issue. Thank you for taking the time to help out
As I said above I think your biggest challenge will be to locate a Cat 8T-8697 ECAP Tool (P49 of the attachment I posted earlier) with the relevant chip (aka SPM) for a PEEC engine and until now no-one has come up with any suggestion of a work-around if you don't have access to one.
The work around is find a advance unit and injector pump off a 3ZJ B model.
Do you know if the ECAP tool is used to store the calibration of the timing sensor or is it just needed to get the sensor set within the working voltage the ecm needs to see? I back probed the sensor and set the voltage range that way by running the advance servo valve with a screw driver (set to .4v- 4.6v). When the sensor is plugged in the timing goes to full advance. I did the sweep test of the timing btm (p-242 in the document you sent) and it moved through the range as it was supposed to and the resistance was in the correct range at 1 ohm, however the voltage started at 2.5 and went to 5.8 instead of starting at 0 and going to 3.6 +/-.3. The total voltage was correct it just started at the wrong starting voltage. In that test, it states if the voltage is incorrect that the ecm is at fault, would that be enough of an indication to prove the ecm has failed?
The nearest comparison I can draw is that ECAP is/was a self-contained computer to use in the diagnostics of the electronics on the 3406/3176/3196 range of engines. Today the equivalent would be a laptoip equipped with Cat ET software which will diagnose almost any electronic system. I suspect so, but I wouldn't like to stake my life on it.
Thanks for the help. thought I would follow up in case anyone has the same issue and is dumb enough to spend the time on the peec system. The timing issue was a combination Of the timing position sensor and the ecm. I pulled the ecm apart and found a diode burned. I resoldered one in place and that didn't solve the issue. Found a used ecm on eBay that solved the timing. It still had an intermittent crank no start or would die and restart. Thankfully it started acting up more often than not and I found the engine speed sensor was dropping signal when it was dying/ wouldn't start. New sensor seems to have solved the issue.
Thanks for the update. Kudos for figuring it out. The PEEC thing was a short-lived mess.
We still dust off out ECAP once a year for a PEEC. Ill grab some pics of it next time. I have been able to hook up CAT ET to them as well.
It would be nice to see how you did that.