NHE 6.5 - Not Getting Gasoline

[bingoldsby]

This is an Onan NHE 6.5 in my 1986 Holiday Rambler Class A 30' motorhome. It is the original equipment. It has run well most years since I have had it - 11 years now.

Twice - once last year, and now again, it has stopped running for what I'm sure is a lack of fuel. The first time I took it to a shop. The fellow said he got it running (didn't say how) but that he didn't like the sound of it and shut it down and went no further with it. It ran great after that, until just recently. About a month ago, it ran fine for about 20 minutes - with load on it - and then stopped abruptly. Wouldn't restart. I gave up and left it for several days. Wouldn't start then.

It fires off just great with a little spray of starting fluid into the air cleaner housing.

I started the Motorhome engine and let it run for about 5 minutes and then tried the generator. It did start and run then. After shutting down the MH engine, the generator died about 5 minutes after that. Fooey! THE GAS TANK IS PLENTY FULL.

This all has made me want to convert the generator to propane, but I'm stuck with the desire to figure out what is wrong with the current setup. What looks like the fuel pump does not look like that which I can find in literature/drawings for this particular model. I'll include a picture of that part of it if I can.

I'd like to obtain a fuel filter and start there, but can't determine if there is even such a filter on this rig. I'd go with a new fuel pump if that was the problem.

I'd rather not have to unhitch the motorhome from my home location in a mobile home park just now, nor do I think I want to get someone out here to work on it.

Any ideas? Thanks!

https://photos.google.com/album/AF1QipNi-_N9XVdaTX0ypraDDp5k78kv4m9fXBg3iW6U

[bingoldsby]

O.P. here, again. My final solution has been to obtain a 6 gallon marine-type (red) plastic fuel tank, with a gauge and 1/4" fitting on it - adapted to 3/8" fuel line fitting. It is very low profile (about 8" tall) and fits in the compartment just to the aft of the generator compartment. It is installed and working perfectly.

I had the underside of the entire motorhome sprayed with expanding foam insulation quite a number of years ago. This old rig is open underneath there up to the floor. But that meant that I could not find ANY of the old fuel line from the main gas tank to the generator.

[MEXICOWANDERER]

Edelman or Weatherhead brand fuel hose is worth the hassle and the cost. So are "constant tension" spring hose clamps. They have a small coil spring. End of fuel hose headaches for a decade or two.

[bingoldsby]

OP here. The generator runs great. It is pulling gas from a gas can through a new piece of rubber fuel line. And when I sucked on the end of the original line I took off the gen,., I just got air and only a little splash of gas after a lot of sucking. Ptooey!

Anyway, there surely is a crack/breach in the fuel line. I have about enough ambition to just keep a supply of gas in a couple of containers and run it just like it is now, or have the propane conversion done. We'll see. I might crawl under the rig and see what I can see of the old fuel line. I hate thinking that it might be broken atop the big gas tank (70 gallons.... and full now), but I'm resigned to the fact that it is possible.

Thanks all for the comments.

Brian

[Chris_Bryant]

MEXICOWANDERER wrote:
This is for my own information -

Do not the NHE Onans use a relay latching network to power the fuel pump?

The fuel pump is run from the circuit board- what method the board uses, I do not know.

[MEXICOWANDERER]

This is for my own information -

Do not the NHE Onans use a relay latching network to power the fuel pump?

[Gene_Ginny]

Chris Bryant wrote:
I get a 404 from the picture url-
https://photos.google.com/album/AF1QipNi-_N9XVdaTX0ypraDDp5k78kv4m9fXBg3iW6U

I get:

One account. All of Google.
Sign in with your Google Account

I don't have a Google account and I don't want one.

[Chris_Bryant]

See if the picture is public- I still get a 404 on both.

[bingoldsby]

Well, fooey, Chris. I get a working link from your reply. I went there, right clicked on the picture, and selected "copy link address" - which I'm going to paste just below.

https://photos.google.com/album/AF1QipNi-_N9XVdaTX0ypraDDp5k78kv4m9fXBg3iW6U/photo/AF1QipMNsxKGcPuANdQpF6eWIHdY2t6u74kV_fwifcNO

Maybe....

[Chris_Bryant]

I get a 404 from the picture url-
https://photos.google.com/album/AF1QipNi-_N9XVdaTX0ypraDDp5k78kv4m9fXBg3iW6U

[bingoldsby]

Well, thanks so much for the responses. All good suggestions. I will indeed try letting it pull gas from a container right up next to it. That will be the easiest first trial. The gen is electrically fed from the motorhomes main 12v system, which indeed has plenty of volts. As far as pulling a solenoid wire (I presume to kill the starter), I'll have to investigate that one. I'm at a place (the Mobile park) where there could be lots of qualified helpers if I can't figure that one out on my own. I must admit that I am a piano player and not a mechanic, but on the other hand, I have been a Ham Radio Operator for the past 55 years also, so I'm not totally electrically disadvantaged.

Also, does anyone have any ideas about what shows in the picture... which I presume is a fuel pump only? It does not look like the drawings in my manual - which I have all of originals - operators, installers, and parts/service. I do not believe there is a fuel filter anywhere near it either. The link I gave did not make a clickable link in my original message, but highlighting it and pasting it into a browser will indeed take one to a picture.

Thanks again folks.... I'll keep you posted, although it might not be for a few days that I get back to it. Wish me luck.

[mchero]

I helped a buddy with a ford Class C that was having issues with the engine running rough. Also had a bad fuel level sender. When he dropped that tank we found BOTH engine & generator pickup tubes severely rusted. The pickup for the generator was actually rusted thru in a couple spots. I assume it would have been sucking air! He had an empty tank when he pulled it.

[Chris_Bryant]

I would bet on a cracked rubber fuel line sucking air. Unfortunately, the bad part is often on the top of the tank. To test get a can of gas and short piece of fuel line and run it off that.

[Matt_Colie]

Brian,

I have two possibilities, both are based on my experience with my own Onan that is somewhat older, but very similar.

You can download the manual at NHE Manual

First is fuel: Can you unplug the wire on the solenoid? If you can, do and hold the start switch. You should hear the fuel pump clicking a fast and then slow down. If you can't get to the solenoid you could do this at the control board, but I don't know your level of technical capability so I don't want to suggest this. Now you know that the pump is working or not.

It can also be a cracked fuel line - Any Place. This is very common with older vehicles as the line age out anyway and the alcohol in new "Motor Fuel" is doing damage to all the old rubber non-alcohol compatible fuel lines. If you can't find a crack, just get some new line and replace it all.

The next is the "shuts down after a few minutes problem.
Does the unit have its own battery? If it does, check the running voltage. The charging system is cheap and dirty and can fail easily.

Good Luck

Matt