Community Forums

vito.a · 10-18-2017, 11:32 AM

Next time it starts chugging, let off the acelerator, count to 3, then stomp it. That usually will clear it up for a short time. Many of us carry spare fuel filters because this issue is so common.

A Traveler · 10-18-2017, 06:49 PM

Quote:

Originally Posted by tommar

One other thought. Does your Allison tranny have an economy mode? In economy, it shifts differently. And you don't get as much power.

This is not correct. All the economy mode does is change the shift schedule at wide open throttle. The transmission will upshift at a lower RPM when in economy mode. It does not change the power output of the engine at all.

tommar · 10-18-2017, 07:18 PM

Disagree: economy mode does NOT change shift schedule at WOT (wide open throttle). The shift schedule is changed at all RPM. Example: in non economy mode, you may be running at 2300 RPM at say 55. Turn on economy mode, watch your RPMs go down to say 15 or 1600 RPM. So less power. Engine is working slower.

However, other posters as well as the OP are indicating that the engine is "chugging" ie not running smoothly. So yes, it makes sense to check filters as well as water separator.

nehog · 10-19-2017, 04:37 PM

Quote:

Originally Posted by psandoz

Thanks to all the readers and great advice. When we get home next week first order of business is change the fuel filter and drain water in fuel. I'll keep the forum posted of progress.

You can drain the filters quickly on most coaches. Mine it is a five minute job. Generally if your drain filter light is not on, there probably isn't much water in the filter.

staggerlee · 10-19-2017, 09:07 PM

If it is always chugging when you go to a stop light, or sign, you are pushing your luck.
You will shut it off at some point, and when it don't start, a tow truck is not to far away. Don't ask.

Mine chugging because I towed a trailer to Tex. and ran out of fuel. Suck up the bottom of the tank. I'm going to change that fuel filter as soon as Wife lets me use her car to get a new filter.

chunker · 10-20-2017, 09:38 PM

Quote:

Originally Posted by psandoz

Thanks to all the readers and great advice. When we get home next week first order of business is change the fuel filter and drain water in fuel. I'll keep the forum posted of progress.

I would drain the water separator right away. As said, doesn't take any time at all. When I do mine, a few times a year, I put a small jar underneath to catch and inspect the fuel. Peace of mind.

psandoz · 10-29-2017, 07:30 PM

Thanks for the responses and here’s another question. Are there two separate filters on these engines? On the top of the engine is a NAPA 3585 that fits in the canister. As I’m draining the fuel/water using the release valve I discovered another fuel filter/water separator underneath - NAPA 3405. I opened the bottom fitting and drained about 3 cups of mostly water. Is there another filter on there to replace? I tried to turn it but it didn’t spin. Thanks.

Ray,IN · 10-29-2017, 10:02 PM

I too recommend changing fuel filters first.

Quote:

Originally Posted by tommar

One other thought. Does your Allison tranny have an economy mode? In economy, it shifts differently. And you don't get as much power.

Economy mode causes the Allison to keep engine rpms lower to save fuel by upshifting sooner at acceleration, you have the same amount of power you're just in a higher gear. Keep in mind maximum torque is at lower rpms, higher hp is at higher rpms, but with less torque.

Whaler2 · 10-30-2017, 10:12 AM

Fuel quality cannot be overstated. A 5.9 with a VP 44 is a very costly repair waiting to happen if you don't keep the filter/ filters in good condition and water drained off. Some have only one filter with the wif indicator and drain. Always make sure the o ring is used with the spin on filter or dirty fuel will by pass the filter element and make a very short service life of the VP 44 which is very sensitive to water and over heating of the imbedded electronics. I do not recommend draining off water while engine is running. You may get a diesel bath.

Ray,IN · 10-30-2017, 10:37 PM

Quote:

Originally Posted by Whaler2

Fuel quality cannot be overstated. A 5.9 with a VP 44 is a very costly repair waiting to happen if you don't keep the filter/ filters in good condition and water drained off. Some have only one filter with the wif indicator and drain. Always make sure the o ring is used with the spin on filter or dirty fuel will by pass the filter element and make a very short service life of the VP 44 which is very sensitive to water and over heating of the imbedded electronics. I do not recommend draining off water while engine is running. You may get a diesel bath.

Buying the cheapest fuel one can locate, sometimes turns out to be the most expensive fuel.
On the 5.9, opening the water drain while the engine is running sucks air into the fuel system. The VP44 is cooled by fuel flow, air in fuel can cause a major problem.

chunker · 10-31-2017, 05:11 AM

Quote:

Originally Posted by psandoz

Thanks for the responses and here’s another question. Are there two separate filters on these engines? On the top of the engine is a NAPA 3585 that fits in the canister. As I’m draining the fuel/water using the release valve I discovered another fuel filter/water separator underneath - NAPA 3405. I opened the bottom fitting and drained about 3 cups of mostly water. Is there another filter on there to replace? I tried to turn it but it didn’t spin. Thanks.

You do apparently have 2 filters. If your asking about a third, I doubt it. I have 2 and only one has a drain. Again, I check several times a year. A couple times I have gotten the "water in fuel" light come on but only when driving in hard rain a while. The first time it happened I pulled over and drained the filter in a heavy rain. No water except on me. I've since discovered that it's a connection someplace that doesn't like water. I put dialectic grease on the connection closest to the filter but a couple time since got the light. Didn't happen this year but also didn't drive in very heavy rain. Only while driving a while in very heavy rain. When servicing this winter I'll clean and grease the connection again and see if I can shield it some.

Water is an enemy to the systems. Drain to from fuel and air systems. Keep it in the cooling and all are happy.

psandoz · 10-31-2017, 07:26 AM

Update. When we got home I changed the fuel filter (3835) and it looked a bit dirty, however the fuel drain valve will not reseat and now diesel runs out. And I emptied the fuel/water seperator filter (3405) and got a lot of water. I was thinking it would drain the filter only but it looks like now it is draining diesel. Any further thoughts? Thanks for all the good advise.

psandoz · 11-02-2017, 09:02 AM

So I changed the fuel filter and drained the water in the water/fuel separator, that made quite a difference as I test drove it. Will find out for sure in a few weeks when we make our Thanksgiving trip.

But like most things, when I opened the drain valve attached to the fuel filter, it would not reseat, so I ended up changing that out. Glad I didn't do this on the road.

Thanks for all the good advice.