Motorhome sudden difficult time accelerating

[majicchuck]

We started heading back from Orlando yesterday. About six hours in I noticed that the coach was having a tough time accelerating. With my foot to the floor it barely got up to 60mph. Then it really struggled to climb the hills. Several times it crept up a hill at 25mph. Acceleration from a stop was beyond slow. Seems like a fuel delivery issue (pump or clogged fuel filter). However, fuel filter was replaced six months ago. Finally, had to find a Walmart for the night. Has anyone had this issue with a CAT engine?

 

[Ranger smith1]

That is usually a fuel filter issue. Maybe have algae in diesel and filter picked it up plugging filter. Happened to me. Plugged filter almost solid. I always carry a spare now and a gallon of diesel to fill it.

 

[Utclmjmpr]

That description for a diesel will almost always be a fuel filter, usually the primary, it does not mater when it was replaced last, you can get bad fuel anytime and that is why its there.  Always carry a spare.>>>Dan

 

[A Traveler]

Was there any black smoke from the exhaust? I ask because this lack of power can also be caused by the air induction hose coming off the turbocharger. Guess how I know this...?

If there was smoke, that means not enough air.

No smoke means not enough fuel and the filters are the first thing to check.

 

[John From Detroit]

Friend of mine owns a beautiful vintage (over 25 years old) Blue Bird Bus
First the Generator gave him issues (Would not keep running)
Then the main engine Oh he'd put in a new Primary Fuel filter (Do not know about the secondary, yes that bus has two in series) but still the improvement was only brief.

He just knew they replace "A" fuel filter (The primary)

So the mobile Tech replaced the secondary. No improvemnet. I was chatting with him and ask about the primary filter. Oh I knew what is was but rather than embarass the tech I ask. Oh, that is the Primary filter.. He pulled it out.. Algae all over it.

Dropped in a new one and sold the guy a bottle of Algae be gone and he was good to go.  Just like that.

25 years and He'd never had an Algae issue before.... Seems they used to pre-treat the fuel before they sold it.  but alas. no more. more profit in selling the treatment to you independent of the diesel.

 

[majicchuck]

That is usually a fuel filter issue. Maybe have algae in diesel and filter picked it up plugging filter. Happened to me. Plugged filter almost solid. I always carry a spare now and a gallon of diesel to fill it.

That was my thinking. Thanks. Plan to carry a spare.

 

[majicchuck]

That description for a diesel will almost always be a fuel filter, usually the primary, it does not mater when it was replaced last, you can get bad fuel anytime and that is why its there.  Always carry a spare.>>>Dan

Thanks!

 

[majicchuck]

Was there any black smoke from the exhaust? I ask because this lack of power can also be caused by the air induction hose coming off the turbocharger. Guess how I know this...?

If there was smoke, that means not enough air.

No smoke means not enough fuel and the filters are the first thing to check.

Uh oh There was smoke. The exhaust has black residue. Getting filters changed out now. Was it easy to connect the hose? Need to find where it's located.

 

[majicchuck]

Friend of mine owns a beautiful vintage (over 25 years old) Blue Bird Bus
First the Generator gave him issues (Would not keep running)
Then the main engine Oh he'd put in a new Primary Fuel filter (Do not know about the secondary, yes that bus has two in series) but still the improvement was only brief.

He just knew they replace "A" fuel filter (The primary)

So the mobile Tech replaced the secondary. No improvemnet. I was chatting with him and ask about the primary filter. Oh I knew what is was but rather than embarass the tech I ask. Oh, that is the Primary filter.. He pulled it out.. Algae all over it.

Dropped in a new one and sold the guy a bottle of Algae be gone and he was good to go.  Just like that.

25 years and He'd never had an Algae issue before.... Seems they used to pre-treat the fuel before they sold it.  but alas. no more. more profit in selling the treatment to you independent of the diesel.

Thanks. No issues with my diesel generator. Getting fuel filters changed out shortly. Hoping this solves my issue. Trying to turn lemons into lemonade

 

[majicchuck]

Got fuel filters changed and drained fuel to see if fresh fuel would make difference. No change in acceleration. At a lost for what this might be. No codes are showing on scanner. Stuck in SC at truck repair shop. Ready to get home. Not many repair shops that work in motorhome. Went to Cat repair shop that tries to stay away from Rvs.  Part of me wants to have it towed home.  However that's 11 hours. 

 

[majicchuck]

Okay thought this might be helpful for others. It turns out that the unreal slow acceleration and sudden lack of power was not caused by bad fuel, turbo, or speed sensor. It was bad fuel injectors. While three injectors were bad, I had them change out all six. What a difference! The repair shop struggled to diagnose the issue. It just so happened that the manager knew a guy that was a CAT specialist (he used to work for him) who was known for diagnosing complex issues.  He showed up with his buddy and hooked up the scanner and laptop and was able to pinpoint the injectors. Boy those injectors were quite expensive. 

Safe travels to everyone on the road.

 

[Gary RV_Wizard]

Most motorhomes never see enough use to experience failed injectors, but it's fairly common in pick-up diesels as they roll up the miles.  Dirty fuel can cause it too, if the mix of dirt just happens to be in the range that can escape the fuel filters.

 

[majicchuck]

Most motorhomes never see enough use to experience failed injectors, but it's fairly common in pick-up diesels as they roll up the miles.  Dirty fuel can cause it too, if the mix of dirt just happens to be in the range that can escape the fuel filters.

Yeah I was surprised since the coach barely has 35k miles. I do feel that I gotta bad batch of fuel from an Exxon station. The fuel filter smelled like gas. I?m certain that I put diesel in it.

Oh well as they say sometimes you have to turn lemons into lemonade.

 

[ppars2001]

Ours is a gas and it does the same thing. We will be traveling along and the speed just dies down.  We pull over and turn off .  Turn engine back on in a few minutes and take off, its fine.  Has about 22,000 miles on it. Engine is 8.1 GM Workhorse chasis. W24. Any ideas?  Thanks

 

[Arch Hoagland]

Ours is a gas and it does the same thing. We will be traveling along and the speed just dies down.  We pull over and turn off .  Turn engine back on in a few minutes and take off, its fine.  Has about 22,000 miles on it. Engine is 8.1 GM Workhorse chasis. W24. Any ideas?  Thanks

Do you get a Check Engine light?

Have you ever cleaned your MAF (Mass Air Flow sensor)?

 

[ppars2001]

No check engine light

 

[ppars2001]

Going to change MAF and fuel filter.  Thank you.