Ok, sorry been away from the van for a bit. But today got back to work on the heater (BTW I'm still trying this at 6800 ft)
I did all the maintenance described in this video:
- swapped out the fuel filter (which didn't seem dirty at all)
- opened up the heater and cleaned things out (didn't seem sooty)
- replaced the ionizer screen.
Then I also did a factory reset.
started the heater, took a couple tries to get the fuel back in the line and get the bubbles out. But I did get it to run. Even got it to run for a full hour with me sitting there.
Then I thought I would try an overnight test (set a temp, and set it to infinity time) and see if it was still warm and not errored out in the morning. But I just went out last thing before going to bed. It had errored out. (standard P000129, 8, 12a stuff). Based on the run hours timer it seemed to have worked (turned on and off to meet the thermostat set point) at least a few times and for a couple hours over the course of the afternoon.
I immediately tried to get it started back up again. Failed twice, early in the startup process (inside 3 minutes).
So now I'm off to bed.
Have you inspected the fuel line for cavitation bubbles on startup? Cavitation is more prevalent at altitude. The fuel line connections, if they are not butted right up against each other can add to the cavitation.
Fuel pump angle must be within spec.
I don't think we've solved this by replacing the fuel pump. I do have a spare that I used to rule that out for my issue. If you are near Evergreen, you are welcome to try it.
My van is parked on semi steep driveway currently, but my iphone level says the pump is still at 25ish°. Inside spec. And if I can't get anything else to work I may take you up on that fuel pump to see if I can rule it out. Also, when I'm working on it tomorrow, and if it starts failing again, I'll keep an eye on the cavitation. In my mind I feel like once I get it to work for a while, and haven't moved the van or anything it should just keep working. But that is maybe a bad assumption.
I've never been able to get that noise to go away at high elevation. Heater still works right? It's just noisy? Never starts first try either. Did you try the backpack trick I posted a while ago?
Heyo, I think I must have missed that backpack trick you mentioned reading through this massive thread. But I'll give that a try tomorrow.
Where’s your fuel pump mounted? What Angle? Is it near any heat sources?
My fuel pump is mounted on the drive side of the fuel tank, and toward the front of the vehicle a bit from the standpipe. It is hanging off one of the frame members, and there is not really anything around there.
Def curious if you disassemble to do maintenance whether the failed starts have caused / contributed to a build-up on it. 🤔
Or if the, "block the output," trick helps?
And a "factory reset" for sure.
It still seems crazy what a breadth of experiences everyone has had with these things.
Yeah, so the fuel filter looked clean. And there wasn't really soot that I saw. The atomizer screen had a little rainbow-ish tint like it had been heat treated. But that is the only sign of wear I really saw.
Thanks all for your help, thoughts and questions. I'll try another factory reset, and this "block the output" trick to see if that changes anything.