ISL9 Sluggish on Cold Mornings

[photraveller]

OK, I've got a new one. All three times in the last month I've driven the coach in relatively cold mornings after being cold soaked all night, the Cummins acted really sluggish.

We've driven this coach in the cold before but never noticed the feeling of it being really sluggish trying to get to interstate speeds until this last month.

BTW, all three days have been around 30F. So cold but not COLD. So no engine preheat.

We have about two miles that we drive from our S&B house until we hit the interstate, so it's all 30-40 mph before taking the on ramp.

Then it's like I have half throttle and it really takes a long distance to get to 60-65. Today I noticed the engine temps were over 160 when I started onto the interstate, but transmission was still in the 120-130 range.

Of course by the next time I needed to make a speed adjust, 8-10 miles down the road it was it's normal self. The remainder of each day it was normal.

Before the first trip at Thanksgiving, I was a little concerned about still having summer blend (and Bio?) in the tank, so I put some boost in the tank before I let it sit out in the driveway as we were prepping for departure for a day or two. Since then I've put more than 100 gallons in the 100 gallon tank, so I feel like I should have a good amount of winter blend in the tank.

Any ideas?

Steve

[R.Wold]

Does it have an exhaust brake? If so it might be using this to pre- heat the motor even at 30*

[brobox]

Has the fuel filter been changed. A dirty filter will slow fuel flow, worse when cold.

[Matt D]

If you haven’t thrown any codes, I suspect you got a bad load of fuel.

Change the filters, run it a while, change them again and see how it performs.

We had this on our ISC and it took almost a year and several hundred gallons of fuel through the system to fully resolve.

-Matt

[lwmcguire]

Either a filter or some type of control issue

Take it to a good shop for analysis

[Butte64]

Some experts say that any start with engine temp below 90 is a cold start and most engine wear is from cold starts. That seems extreme but below 40 degrees is definitely cold. Preheat is so easy there is no reason not to use it at 30 degrees. I’ve noticed when I preheat that it cranks much easier so less stress on battery and starter.
Also if your first few miles are in areas with traffic where your speed varies and with stops, turn off engine brake so the transition from from slowing down to going is easier.

[photraveller]

Lots of good ideas thanks!.

Definitely gave me the Ah Ha moment.

While the fuel filters were changed in Oct by Spartan, I did have a concern about algae growth in the tank. Since I screwed up. I talked my advisor that I wanted the fuel checked and explained why. She proceeded to tell me that they automatically check the fuel coming from the old filter and if I had a problem my tech would find it.

Asked the tech about it later and he said "oh... it was fine", but then he was the same tech that forgot to tighten a hose clamp or three while replacing my expansion tank. So looking back,his remark doesn't hold much weight.

End result, I'll start with changing the primary fuel filter in the next couple of days. Hopefully I can get past this morning as we get toward warmer temperatures.

BTW, my screw up: I left the tank half filled during the summer months in my barn in Indiana. The insulated barn helped with big temperature swings , but I didn't run the AC in the barn this summer. So it got warm and humid inside. I know bad idea!

Can't believe that I didn't remember that algae growth fear until your responses. Especially since my mind was dancing around fuel jelling and a clogged filter.

Steve

[photraveller]

Originally Posted by Butte64

Some experts say that any start with engine temp below 90 is a cold start and most engine wear is from cold starts. That seems extreme but below 40 degrees is definitely cold. Preheat is so easy there is no reason not to use it at 30 degrees. I’ve noticed when I preheat that it cranks much easier so less stress on battery and starter.
Also if your first few miles are in areas with traffic where your speed varies and with stops, turn off engine brake so the transition from from slowing down to going is easier.

Jerry, I agree with preheat, but I stopped preheating the ISL9 for two reasons. One Cummins says we don't need preheat for anything above 0F on the ISL9. Second I have a hate/hate relationship with the electric rear hatch. As such I baby the hell out of it. I guess maybe I really should get one of those remote controls for the block heater.

Steve

[photraveller]

Originally Posted by Matt D

If you haven’t thrown any codes, I suspect you got a bad load of fuel....

-Matt

Matt no codes, so yeah bad fuel seems likely.

[brobox]

Steve, my experience with what you just explained. The buyer of my Travel Supreme did the same thing. He was suppose to pickup the MH in Sept. He left it sitting in FL with untreated fuel until Dec with 3/4 tank, 1/4 used in our test drives. He got to Tampa and called me with the same condition you are having. I told him to change the fuel filter I left with the coach. He didn't want to get his hands dirty and elected to drive it to Cummins


By the time he limped in, I believe it was Cummins Ocala, he had burnt the primary fuel pump out and it was a mega repair bill. If you can treat the fuel with an algae reducer and have a few fuel filters on hand would be helpful. It is expensive if the fuel pump is over heated, $1,800 IIRC. Good luck with that, it is not fun.

[Gary.Jones]

And as has been discussed on here many times, you can get a bad load of fuel just as often and easily at an old truck stop as at any small more car type place... Chuck's stated policy is that if he sees a fuel delivery truck in a truck stop dumping fuel, then he doesn't buy fuel there (as he argues that that stirs up all sorts of crap on the bottom). I have taken that advice to heart. I dont buy fuel anywhere that has had a recent fuel fill. Although most big commercial truck stop chains sell a lot of fuel, that doesn't mean their tanks are in good shape, so I often consider the "age" of a fuel stop with preference toward newer operations with newer tanks.

Oh, and standard operating procedure for me is to immediately fill my tanks completely with fuel after arrival from a trip so that my tanks are always filled as far up as I can get them filled while the coach sits in the driveway. I carry Algaecide (sp?) but I have never used it.

Gary

[HJLowell]

Dang
If I see fuel delivery trucks coming and going I stop and fuel up.

With the newer EPA regulations in place, most tanks have been replaced or new stations built with new tanks the past 6 to ten years.

Most newer, last 20 to 30 year old pumps have moisture detectors.
And some filter systems.

We have always tried to buy from busy , high volume outlets.

Doesn't mean that Im correct ?
But just one way to think about it.

1. We carry a spare set of filters.
With all Diesel powered vehicles, equipment.
If the operator experience a slight loss of power or hesitation, he first changes the fuel filter.
2. I change out fuel filters every 6 months.
Regardless of miles driven. On our coach.
On all Diesel engines we are responsible for.
Back hoe's
Dozers
Farm equipment and such.
They get changed on a 6 month schedule also.
The cheapest maintenance an operator can do.

[HJLowell]

Owning a DP isnt always a clean hands experience.
Ten minutes installing a $30. Fuel filter and washing ones hands could have saved him $2 plus thousand dollars.
This is a learning curve experience for certain.
Very good points made by several in this thread.
Thanks.

Originally Posted by brobox

Steve, my experience with what you just explained. The buyer of my Travel Supreme did the same thing. He was suppose to pickup the MH in Sept. He left it sitting in FL with untreated fuel until Dec with 3/4 tank, 1/4 used in our test drives. He got to Tampa and called me with the same condition you are having. I told him to change the fuel filter I left with the coach. He didn't want to get his hands dirty and elected to drive it to Cummins


By the time he limped in, I believe it was Cummins Ocala, he had burnt the primary fuel pump out and it was a mega repair bill. If you can treat the fuel with an algae reducer and have a few fuel filters on hand would be helpful. It is expensive if the fuel pump is over heated, $1,800 IIRC. Good luck with that, it is not fun.

[buddy110]

Originally Posted by brobox

Has the fuel filter been changed. A dirty filter will slow fuel flow, worse when cold.

This was my first thought also