First trip in the books

[windtrader]

After a couple months of "sea trials" (i.e. boondocking) shaking out all the bugs in the new bus, it just finished a 7 day, 1000 mile trip between San Francisco to San Diego. Overall, extremely pleased with the performance.

ONLY things to report. One air valve started a small leak but a few bursts of air and tightening it resolved that issue. The other was a bit more dramatic. Heading through LA traffic is never pleasant but getting your passenger mirror knocked off is par for the course I guess. I was in one lane, a semi was two lanes over, and a tanker in a rush decides to squeeze between us. BANG! WTH was that and the chase was on. I still haven't made up my mind if he knew he swiped it or not but after much honking and waving he finally pulled over and immediately approached me with his hand out. By then he figured out what happened then we start the negotiating. He just wants to make up lost time on a late delivery so offers a hundred. No way, let's call the police and insurance. After a bit of haggling two hundred bucks and we are all good friends. Cost me 25 bucks and some time getting one made at the glass shop.

Maybe a quart of oil used, transmission fluid was fine, coolant was fine, fan box gear fine, power steering maybe a few ounces. Tires fine. Not a single odd noise, squeak, click, whir, rumble!

Learned a bit more about actual electricity usage while on battery. Will switch more bulbs to LED and find other ways to save a few watts. The current bank 24v x 210Ah is barely enough. Probably looking at doubling the bank size, then solar will take care of charging. Need to find high efficiency "house" fans and look for more ways to convert to direct DC.

Learned the speedo is off and 60 on the dial is actually more like 63-64. Bus is most comfortable around that speed too. Feels real light on the pedal and very settled floating down the road.

Ordered a new set of convex mirrors that will make it much easier to see what is going on.

Just thrilled and could not be more pleased first time out. Looking forward to many more journeys.

Humm... there is one outstanding issue. The generator does not stay running on first start. It takes a few attempts and then will keep running. Originally, it seemed the control board was bad but it seems more and more fuel related, either not building pressure quickly or maybe some air getting in lines or something. Maybe it just needs more pre-heat time to get it to stay running. As long as it starts after a few attempts I can live with it but would resolve the root cause.

[RJ]

Don -

Excellent recap.

Question: Who's genset do you have on board?

RJ

[Nick Badame Refrig/ACC]

Hi Don,

Not Bad for your first trip...I would say Success!

Reminds me of my first trip back in 05' But, I had a lot more issues.. Lol


Nick-

[lostagain]

Generator start: if there is a low oil pressure shut down, you might have to hold the starter button down long enough after it starts to wait for enough oil pressure to build. On mine in the bus, you hold the start switch down until the light beside it goes off, a good 3, 4 seconds. On a back up generator at home, I have to hold a by pass switch while spinning the starter and after it starts for a few seconds, long enough to build oil pressure, then release it, and it keeps running. Let it go too soon, and it quits.

JC

[richard5933]

JC - Sounds like you have a Murphy switch set up like mine. They can be set up with the button to hold in until oil pressure gets high enough, or like mine with a built-in delay. I went with a 30-second delay, but there is also a 15-second option. It gives the engine that preset amount of time (15 or 30 seconds) to build pressure. If it doesn't build in time the engine shuts down. Important to remember that the timer starts when the key or power switch is first turned on, not when the engine starts. If you've got a 15-second timer and it takes 10 seconds of cranking to start, then you only have 5 seconds to build oil pressure. I learned the hard way when I had air in the lines I was trying to purge. I cranked a bit, then stopped, then cranked a bit, etc. Problem was I didn't turn off the key between start attempts. In the end, the thing timed out and the Murphy switch cut power to the governor. Took a minute of panic to realize what was going on. Turned off the key to allow it to reset, and all was good for another attempt.

If you do have a Murphy switch gauge setup, check to see if you oil pressure set point is too high to allow for start up. Should be set just above the lowest safe level for running, not at the full pressure level.

Richard

[windtrader]

@RJ Generac 8Kv NP80. It's been a couple moths living with the qurkiness of the intermittent starting. I have tried all the various combinations of holding prestart down and that circuit is inline of the problem bacause no matter how long the generator has been running brfore it quits if that prestart button is held down the gen will stay running. The instant that button is released, it immediately shuts down. I am certain that it is not a mechanical problem but electrical in nature and everytime I trace it source it keeps pointing at the control board having some short or failing component. I found  a place that supplies gen control boards for fair price but will see if a locall elec tech can find the board issue first.

[luvrbus]

Clean the brushes,holders and the slip ring they have to see ac current before it will stay running

[windtrader]

Clifford,
Are those parts inside the alternator? I can only see one cover on the end that one can access without removing the entire head from the engine.

Opened control box again and took some pics for reference. It all looks fine, checked and tightend all connections and wires again.

Sometimes, it still feels like a lack of fuel issue. I'll a fuel pressure and volume test, replace the filter, etc. cheap stuff to try

[richard5933]

Do you have an oil pressure gauge and an engine temp gauge? On my setup, the set points for oil and temp are made directly on the gauges. They are call switch gauges because there is a small 'needle' which can be set with a hex wrench at a particular cut off point. If the gauge needle crosses the set point it grounds out the Murphy switch and immediately kills the engine. My setup has a built-in timer to give delay for oil pressure to build on start up. Other systems use the button like yours to bypass the system during startup.

Once the button is released, if the oil pressure or engine temp hits the set point it will shut down. Perhaps your oil temp sensor or your engine temp sensor is giving a false reading to the shutdown circuit. Try unplugging them one at a time to see if the engine keeps running. Most of them are designed to cause a ground connection, so by unplugging the sensor you eliminate the possibility of the ground.

My setup has the gauges mounted on the engine, but the shutdown circuit is contained within the box on top of the generator. If the generator seems to run as long as the button is held in then that would confirm for me that the problem is most likely in the failsafe shut down system.

Richard

[luvrbus]

Is that Generic a belt drive ?,most older Generic have a LOR low oil relay when you hit the starter it by passes the oil sensor those go bad and cost 5 bucks at NAPA

[Geoff]

I have worked on a lot of Generac's and they are the biggest piece of sh#t with their control boards. I just rewire the generator to normal wiring and they work fine.

--Geoff

[windtrader]

@Richard- There are three ways to trigger motor shutdown: 1) oil pressure low, 2) coolant high, 3) RPM/cycles overrun. I've checked and replaced the oil and coolant switches. Still same issue. Now working with tech at flightsystems.com to check the rpm/cycles shutdown. Tech says if motor runs just higher than cutoff setting from pot on board, motor will stop. However, on this motor (Shibaru 954cc) the throttle seems to be fixed by two screws. Not sure how it puts more fuel in when under load. Checking that now.

Clifford - Generac iNP-80D is a direct drive, motor is directly attached to alternator. Both low oil pressure and high coolant temp switches have been tested. Working on the testing last cutoff circuit.

@Geoff - Surely would not buy a Generac today due to lack of support and parts from OEM. But 20 years ago it was a reasonable choice.

It seemed maybe it was a fuel delivery issue and I checked today to ensure there was sufficient flow into the motor from the fuel pump. It was fine so something else; back to cutoff switch circuit. It definitely runs when pre-heat switch is held down and stops immediately when released. The root cause is connected to this circuit.