330 hp cummings diesel, low power problem


Buck 1

New Member
I have a 99 mountonaire, bought used about two years ago. Low mileage, good shape
My ? is that it seems to have not enough power when taking off at a standstill at times, also I noticed that it would give me problems when backing up a steep grade or even going forward. I talked to a fellow camper which owns a 2000 mountainaire, and said that he had a simular problem, and was told that it was a allitude switch or something like that. Anybody out there ever heard of having a simular problem?? Any suggestions Thanks
 

elkhartjim

Senior Member
Re: 330 hp cummings diesel, low power problem

When was the last time you changed your fuel filter? Just a guess.
 

elkhartjim

Senior Member
Re: 330 hp cummings diesel, low power problem



I guess the first question should have been...what kind of engine? diesel or gas? If diesel I would go to Cummins or Cat web site and also freightliner, spartan, etc. I'm not much help on gassers.

Shame on me, 330 Cummins.
 

C Nash

Senior Member
Re: 330 hp cummings diesel, low power problem

Recond it's a 330 cummins gasser Jim :laugh: :laugh: Sorry just had to do that Jim. The filters still could be bad even though you changed them recently but think you would have problems at higher rpm if they were clogged. Like Jim said might get an answer from the cummins web site.
 

dbarton291

Senior Member
Re: 330 hp cummings diesel, low power problem

I would suggest you take it to a Cummins distributor and have them put the vehicle on their chassis dynamometer to find out if the engine is performing properly in terms of power at the wheels.
 

Buck 1

New Member
Re: 330 hp cummings diesel, low power problem

I sure will let you guys know. Been at an FMCA rally in Essex junction VT. just got back. I e-mailed cummins over the weekend, waiting for there reply. If I don't hear from them soon, I'll take it to have that DYAMOMETER test done on it. Thanks for advice. Boy it seems like it's one thing after another.
 

C Nash

Senior Member
Re: 330 hp cummings diesel, low power problem

But just think how bored you would be if you didn't have the rv Buck 1. Oh by the way "WAR EAGLE" :laugh:
 

Darwin

New Member
Re: 330 hp cummings diesel, low power problem

Buck
I think you will find that the cummins does not have a lot of power on low end. I have a 300 Cummins, from a dead stop I do not have much power, as RPM,s increase the power increases.
Darwin
 

dbarton291

Senior Member
Re: 330 hp cummings diesel, low power problem

Darwin - 8/16/2008 9:19 PM

Buck
I think you will find that the cummins does not have a lot of power on low end. I have a 300 Cummins, from a dead stop I do not have much power, as RPM,s increase the power increases.
Darwin

That's true. Smoke controls limit the fuel available at the low end on most modern diesels. I've spoken with several motorhome owners that thought they had power problems when in reality, the engine was putting out all it was supposed to.
 

Buck 1

New Member
Re: 330 hp cummings diesel, low power problem

Sorry that I didn't get back sooner to you folks, but I just got it checked out today.
Well the past week and a half, I have been on the phone with Cummins,Allison,and Spartan people, and a few others.I finally got it into the shop today. Cummins said check for air leak that serves the turbo, (already done that) also when I replaced the coolant radiator last month on that beast, I had him pressure test the Air turbo raditor. alls fine. they also said that there is not a place near me that has a "Dynamometer machine" Allison said: Change the fuel filters again! can't be anything wrong with that 6 speed! The spartan guys at the rally said maybe the torque converter is locking up????better give Allison a call. Finally I got it into a local shop today, that is a authorized dealer for allison, they put it on a computor, and found out that the "speed sensor on the engine was faulty"the tech said, that allison is one tough transmission,can't be that! Have to wait for the part to come in. hopefully that will take care of the problem. Also I was told that I have a Algae problem, that is growing in my fuel tank, and to buy a product, that is in there parts department to take care of that problem. It's put out by power + or something like that.He said that if they set around to long, that it start growing in there. never heard of that before, than again I never owned a diesel powered motor home. By the way, I changed out every darn filter that came with that rig, I did fine, when I changed out the transmission filters, there was a 10 / 98 stamped on them, could be that they were never changed??
Again, when I bought it two years ago, it only had 22,300 miles on it. You know maybe I can't get much more power out of it, I'll have wait and see when I get it back to try it out. "Bucky"
 

C Nash

Senior Member
Re: 330 hp cummings diesel, low power problem

Hey Bucky, maybe that algae will fermit and make more fuel :laugh: . yes, this can happen in diesel fuel if left sitting. Hope the speed sensor fixes your problem.
 

dbarton291

Senior Member
Re: 330 hp cummings diesel, low power problem

How did the Allison guy know there was an engine speed sensor problem? Trouble code in the engine ECM?

No place around that has a chassis dynamometer? Where are you?
 

Buck 1

New Member
Re: 330 hp cummings diesel, low power problem

He did a diagnostic test on the engine, and it showed that it failed 25 hours ago. but then again the computor says that it was working when he did the test??? I was told that if this sensor is not working properly, that you couldn't get over 1500 rpm, so that must have been the problem as to why I could not move up that steep grade. Any other time, it seems to run just find. I'm in Concord, NH
 
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