Community Forums

FFaust · 10-03-2015, 03:36 PM

Were away last week and this happened 4 days in a row with freezing temps at night and ~65 deg during the day.

Start gen in the am and it quits after a few minutes as if running out of fuel. Loaded or not doesn't matter.

Multiple attempts to restart give the same result: Gen wants to fire up but quits. I can prime it all I want, but still no start. I can hear the fuel pump if I crawl underneath the coach.

Then, mid-day, or when it's warmer, the gen eventually starts and runs fine. I still have to try a few times (to get the fuel up?), but after 3 or 4 attempts, it starts and runs normally.

We run it for a few hours at night and all is fine. Then, the next morning, it's the same story all over again.

Fuel tank is full; filter was replaced this spring; no lines are kinked that I can see... so that leaves the fuel pump.

Picked up a pump from Cummins so that I could replace it over the weekend.

I'm in there now and with the lines disconnected, but the pump is pumping. Temp is 40ish.

The pump cost me $200, so I would rather not replace it if that's not the problem.

Any ideas out there?

Could it be the governor? or?

dennis45 · 10-03-2015, 04:00 PM

Assuming this is diesel, have you changed the fuel filter? Either gas or diesel, I would start with fuel filters and check the air filter.

And No, the governor will have no bearing on this issue. My bet is on a fuel or air related problem.

FFaust · 10-03-2015, 05:24 PM

Thanks, and yes, it's a diesel.

Fuel filter was replaced earlier this year.

Yes, it sounds/feels like a fuel starvation problem.

Everything back together now and gen works fine, but it's not that cold.

I can lie on my back, under the gen, and hit the switch to prime and listen to the pump; it sounds good. All I can hope for is some freezing temps in the next few days so that I can repeat this 'sound check' and see if it sounds any different; I really feel like it's the pump but would like to prove it before replacing it.

tom77hmstd · 10-03-2015, 05:32 PM

If your 8000 is like mine it is computer controlled and it sounds like you have covered mechanical issues. The start switch on the unit will blink the trouble code that is shutting you down go from there. The easy ones are 1 blink for oil 3 for hot.

dennis45 · 10-03-2015, 05:35 PM

Maybe it's just telling you to go somewhere warm...

A pump typically either works or not. I can't see it being temperature sensitive unless we are talking extreme lows but then there are other problems.

Another possibility is a loose elecrical connection?? Can you hear the pump operate when you have the no start problem?

Another thing you might try is to pull apart the connector on the umbilical control cord off the generator, clean with some contact cleaner and resemble with a dab of dielectric grease. I had starting problems with mine and in desperation, tried cleaning these contacts. Have not had a problem since.

FFaust · 10-03-2015, 06:42 PM

Quote:

Originally Posted by dennis45

Maybe it's just telling you to go somewhere warm...

I like the way you think.

I can't really see a connector being so temperature dependent, but yeah, maybe.

Pump is a physical unit so it could act up in lower temps if it's marginal, no?

Tom, the code is 36: Un-commanded shut down, but we know that, lol.

brian-nicola · 10-03-2015, 07:47 PM

Found on a previous post from 2014

http://www.irv2.com/forums/f112/onan...-a-222812.html

My error code 36 was resolved by unplugging my AGS (automatic generator start). After running without for an hour I reattached the AGS and all was fine. Turns out AGS has a history of sending error messages without cause, according to Cummins.

dennis45 · 10-03-2015, 08:04 PM

Quote:

Originally Posted by brian-nicola

Found on a previous post from 2014

http://www.irv2.com/forums/f112/onan...-a-222812.html

My error code 36 was resolved by unplugging my AGS (automatic generator start). After running without for an hour I reattached the AGS and all was fine. Turns out AGS has a history of sending error messages without cause, according to Cummins.

Poor connection maybe?

C-PHartley · 10-04-2015, 12:10 PM

Jelled fuel? Maybe try a fuel additive for cold weather.

Sent from my iPad using iRV2 - RV Forum

FFaust · 10-04-2015, 05:25 PM

Quote:

Originally Posted by C-PHartley

Jelled fuel? Maybe try a fuel additive for cold weather.

Sent from my iPad using iRV2 - RV Forum

Hmm, that makes sense, but at 32ish degrees, just around freezing?

It's exactly what it feels like, but I doubt that summer fuel could be 'that' bad...

bluepill · 10-04-2015, 05:33 PM

Just thinking. If there is water at a low point in the fuel system, it could be freezing and blocking or restricting the fuel flow. Water is heavier than diesel, so it naturally wants to stay in any low area.

Suggestion: Next time you have the problem after a sub-freezing night, try heating the fuel lines and filter with a hair dryer for 15 minutes. See if that cures it.

If there is an easy place to take a fuel sample, you can look for water.

TQ60 · 10-13-2015, 07:59 AM

Or flush the line.

Engine consumes fuel at a slow rate so water could settle over time.

Remove line from output of primary pump to bleed line and pump a bunch into a catch pan...about a quart to gallon...maybe use a gas can.

Normalize the coach then let fuel stand and later check for water at the bottom.

And connectors are very temperature sensitive as many are plated metal contacts and they move a bit with temp changes.

One of the most difficult to properly troubleshoot...

FFaust · 10-13-2015, 05:53 PM

Thanks guys, I was hoping to come back and report, but we haven't had freezing temps since.

Purchased a pump from Cummins for $200 (yeah, it's rough up here with the exchange rate) but will bring it back for a refund until I can prove that that's the problem.