Microquiet 4000 Shutting off

[Henry J Fate]

Update.... Had some time out on the road to look at a few things. After thinking about Gary's suggestion to look at voltage, I set up my volt meter and fired the generator up. The generator was at 122 volts under no load. After turning on the a/c, I watched a decline to 111-112 volts just before the generator shut down on a code 15. I restarted the generator, removed all loads and adjusted the governor screw approx one turn which brought the rpm up with an increase in voltage to about 125 volts. I then engaged the a/c and watched the voltage dip to about 114-115 holding steady. That was over an hour ago and it is still holding at 115 volts with max a/c in mid 90 heat.

The manual calls for 125volts no load and 112volts max load. I think the range is now within spec.

I believe it was an rpm problem. For some reason the generator fell a little out of spec. I suspect the problem is resolved and if everything goes as planned on this trip, I will be heading back to cummins late next week to return the fuel pump.

I will update things when I return to south Florida on Tuesday. If anything changes I will update sooner.

Thanks to everyone for the support. A special thanks to Gary who encouraged the use of a volt meter which ultimately got me to this point today.

Have a good week and upcoming weekend everyone

Henry

 

[Mosagra]

My generator is very similar to yours.

I spent a year fooling around with it, it was the fuel pump all along. The key indicator to me is that it fails with heat and or high load.

It started acting similar a couple weeks ago (4 years after original problem), I replaced that fuel pump asap and now carry a spare.

 

[Heli_av8tor]

Henry, at some point you are going to have to replace the fuel pump if for no other reason than to just prove us all wrong. ?

Said with tongue half planted in cheek.

Tom

 

[Henry J Fate]

Update... The generator continues to operate without any issues. I increased the load by adding in the fridge and the battery charger/converter. Even heated some water in the microwave without issue however at that point, voltage was declining to a concerned level but it survived. The generator ran for more than six hours yesterday under good load. Woke up this morning and fired it back up. Running fine with wonderful a/c and switched the fridge over to 110 again. Runing for an hour no problem. Voltage is holding at about 114v.

After reading Mosagra's post late last night, I woke this morning thinking that maybe I should keep the pump around rather than returning it.

Tom, I am not completely convinced that the pump isn't involved with this event but it is seeming less likely. I am leaning towards a governor assembly that weakened some over time. The rpm range seemed to be the proper spread from no load to full load but the location of the range had fallen some. In my opinion, the change would be consistent with a weakening governor assembly which I believe has a spring or springs and moving parts. A spring would certainly be a suspect probably losing a little spring rate and causing the rpm set point to lower some. My guess is that it went below spec by a tiny 100 rpm. Less than 5%. One other thing that's on my mind is the fault code 14 I got couple days ago. Seems odd that a low out of spec set point would surge to 70Hz for 3 seconds. That would be a large swing in rpm roughly 20%. Ya, maybe I will keep the fuel pump Mosagra.

Henry

 

[Heli_av8tor]

Some of the Kill-a-Watt meters also measure frequency. Should be a good way to set the governor speed.

https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

 

[Gary RV_Wizard]

I suspect your genset engine tuning has deteriorated a bit, or maybe the fuel has a bit less energy than what the original tuning was calibrated for. Apparently your genset performance got a little bit beyond the rpm range the governor could handle, so your manual adjustment helped it along.

I wasn't even aware a Microlite 4000 had a manual adjust. Maybe later years do not.

 

[Henry J Fate]

Update..... All is well. Generator continues to handle all that's needed. No problems. Estimated running time since the governor adjustment is approx 20 hours.

Thanks for the link to the meter Tom. That looks like something I should have and maybe something I could use for my custom control panel which I have been thinking about recently.

Gary, my unit is a MicroQuiet 4000 spec J. There are many variations and I am not sure of what spec has what features. I think the MicroLite followed the MicroQuiet series.

Henry

 

[udidwht]

Update..... All is well. Generator continues to handle all that's needed. No problems. Estimated running time since the governor adjustment is approx 20 hours.

Thanks for the link to the meter Tom. That looks like something I should have and maybe something I could use for my custom control panel which I have been thinking about recently.

Gary, my unit is a MicroQuiet 4000 spec J. There are many variations and I am not sure of what spec has what features. I think the MicroLite followed the MicroQuiet series.

Henry

Which screw is used to adjust the governor for wattage? Any pics-video? Could be grateful to those out there.

 

[Henry J Fate]

Update.... Back in south Florida. Generator runs really good. Got about 36 hours clocked since governor adjustment. Seems to be working as designed. Brought back the fuel pump. Charged me a 15% restock fee. Another RV scam but paid it.

Next week I plan to check the valve adjustments. There are two valves. Intake and exhaust. With valves fully closed there should be 2 thousands of an inch clearance between the rocker arm and the valve stem. This is important for efficiency. I suspect they may be slightly out of spec.

Udidwat..... Before attempting a governor adjustment I strongly recommend to read the service manual for your specific unit and go from there. I think all MicroQuiet series units have the adjustment screw but cant be sure. The service manual is the best source of proper procedure. I would suggest to keep this thread as a record of a fault code 15 cause which appears to be a motor rpm adjustment and wasn't the all to often fuel problem. Service manuals are available for all the Onans. If you cant find the one your looking for, post a thread here and I am sure you will be successful.

That's it for today. Have a good week everyone and thanks again for all the help

Henry

 

[udidwht]

Update.... Back in south Florida. Generator runs really good. Got about 36 hours clocked since governor adjustment. Seems to be working as designed. Brought back the fuel pump. Charged me a 15% restock fee. Another RV scam but paid it.

Next week I plan to check the valve adjustments. There are two valves. Intake and exhaust. With valves fully closed there should be 2 thousands of an inch clearance between the rocker arm and the valve stem. This is important for efficiency. I suspect they may be slightly out of spec.

Udidwat..... Before attempting a governor adjustment I strongly recommend to read the service manual for your specific unit and go from there. I think all MicroQuiet series units have the adjustment screw but cant be sure. The service manual is the best source of proper procedure. I would suggest to keep this thread as a record of a fault code 15 cause which appears to be a motor rpm adjustment and wasn't the all to often fuel problem. Service manuals are available for all the Onans. If you cant find the one your looking for, post a thread here and I am sure you will be successful.

That's it for today. Have a good week everyone and thanks again for all the help

Henry

I have an Onan Microquiet 4KYFA26100B and I just did the valve adjust a week or so back. Generator runs well but was also curious as to adjusting the governor if it needed it at some point. I do notice a couple at the top between the generator and cover tucked behind the PCV hose. The spec for the lash was 0.0008 to 0.0032 I set them to .002

My generator has 514 hours now. Outside of the lash spec there was nothing regarding procedure for governor adjustment. The lash prior to adjustment was still within spec for both valves. The intake measured .003 and the exhaust was a slightly snug .002 prior to adjustment. Also changed the fuel filter.

 

[youracman]

I have an Onan Microquiet 4KYFA26100B and I just did the valve adjust a week or so back. Generator runs well but was also curious as to adjusting the governor if it needed it at some point. I do notice a couple at the top between the generator and cover tucked behind the PCV hose. The spec for the lash was 0.0008 to 0.0032 I set them to .002

My generator has 514 hours now. Outside of the lash spec there was nothing regarding procedure for governor adjustment. The lash prior to adjustment was still within spec for both valves. The intake measured .003 and the exhaust was a slightly snug .002 prior to adjustment. Also changed the fuel filter.

udidwat-  I have a SPEC K and, after reading about Henry's troubleshooting and fix, I have ordered a freq meter to use (together with my DVM) to ck the output and see if my genny is on the "upper end" of the spec voltage/freq-wise.  In addition to the service manual for mine (SPEC J thru L) I also have a manual for "Pre-SPEC J" and will try to post pics of the pages for the earlier Onan re gov adjustment.........hoping they will be of help with your SPEC B should you need them in the future.

Safe travels.................  ed s

 

[youracman]

Hmmmmm- I haven't posted pics here before (that I can recall) so I may well have a bit to learn.  Anyway..... if I click on the images they expand to full size........hopefully that works for you too. 

ed s