no power going up hill in diesel 275 cummins

[Nolotam34]

No power going up hills in our 2001 Fleetwood 275 Cummings. We have taken it twice to the Diesel mech and they can not find anything wrong. It does it pulling and not pulling our TJ wrangler. We are pushing the pedal to the floor and cannot get it over 30 mph. It does find on straight road and going down hill. Any one else have this problem and can give advice

[beenthere]

if your coach is 40' then you should be down shifting as you rpm's drop to max torque...or is is downshifting just not soon enough?? as this engine at about 600lbs of torque is probably usual...jeff

[Old Scout]

Could be a number of things concerning the fuel system but a leak/problem with the turbo boost [eg. turbo, piping, or CAC]. Another issue [cheaper] is simply that the fuel filter[s] is/are dirty.....If there is alot of dirt in the fuel tank, it may take several filter changes and or draining/flushing the fuel tank.

[beenthere]

here is a post in the Cummings forum

Cummins power
Okay... just returned from a 3,000+ mile winter trip and have a lot of questions and issues. This one is; who of you have added performance chips to your ISB 275 HP Cummins, and do you see a significant improvement in power and/or mileage? Mine does fine on flat or gently rolling ground but suffers badly on long and/or steep grades. I can live with it, but 35 mph on Interstate grades is not fun!
__________________
'99 Diplomat 38A- "High Plains Drifter"
'02 Wrangler Tender

[John Wayne]

beenthere you can chip it for more power BUT I think you will find that the trans. can't take the extra torque and you'll have more problems then going up the hills slow.

[Old Scout]

OK--thought this was a recent issue as opposed to always lagging on hills--that is why I suggested turbo boost or fuel filter issues. Argueably, a 275hp engine is a bit small compared to newer coaches. Each engine has its own torque band where the engine is putting out the most HP and torque at a given RPM. This band would differ by engine but assume it has to be between say 1500 and 1800 RPMs for your engine. You may have to manually shift the auto transmission down to keep and maintain optimum RPMs on a hill climb. As a side bar, higher RPMs usually results in better engine cooling during the climb as well.

[Coaster1]

In the case of our older/less powerful diesels. knowing what is happening is the only way to really diagnose a problem. Gauges are everything! Fuel pressure= can spot a dirty filter or bad lift or injection pump. Boost gauge= loose or leaking clamps/hoses on air intake/exhaust systems. EGT gauge= high exhaust temps, waste gate problems,
lugging engine. Trans temp, self explanatory. JMHO, yours of course may vary.

[pwf16129]

had a friend with this problem i did the basics air filter six years old, fuel filter three years old then had to send him to the shop, they found a slight leak on the hose on the charge air cooler but the main problem was the throttle linkage need adjustment it had slipped slightly and wasn't getting full throttle
they tightened the clamp on the cac hose and set the throttle and it ran better then ever just another thing to check

[Greek501]

I have 2008 r.v with 325 cummins when i start up a hill red warning lite comes on and i slow down 20 or 25 it down shift to second. On level road lite goes out and it runs great it. Had it in shop several times. Fuel filters. Retorqed fuel tubes .and replaced speed sense sw. Also had it dino tested .it does not happen all the time?

[charles tuit]

I have a 275 HP ISB. With coach loaded and toad I travel @ approximately 27,000 lbs. I live in the south west and mountain driving is frequent. Keep the RPM's above 2,000 and you will not drop below 45 MPH on most climbs and the temps will stay cool.

[Wizard]

On anything over about 5% grade for any length, I have to manual downshift and I try to keep the RPM's around 2000. Seems to work for me.

[Arch Hoagland]

Has it always been this way or is it just recently?

[Sky_Boss]

Assuming all other mechanical issues are fine...GEAR DOWN!

As previously said, get your RPM up to 2000 or so. If you are full throttle and it drops below 1900...gear down again. Anticipate the climb. As you start up, gear down to 2100 or so and if you hold that, GREAT! If it gets below 1900, gear down again. IGNORE THE SPEEDOMETER! Watch your RPM, water and transmission temps. That being said, you may want to adjust the RPM suggestions I made based on your engine's max RPM but these shouldn't be very far off.

Even with my bigger 400 HP Cummins, I gear down. Why? My motor can handle my rig and toad fairly well in 6th gear even up through 6-7% grades. Any clue what your turbo boost must be to do that? HOT.

Dropping a gear and ignoring the speedo does a couple things, well, at least in my motor.

1. Circulates water faster through out the cooling system.
2. Revs the radiator fan up helping cool things down.

As an example, when I hit Mount Eagle on I-24 between Nashville and Chattanooga I enter the climbs @ about 1650 RPM (62ish MPH) with about 199* water and 203-205* tranny temps. Just as the climb starts and the truck lanes begin the speed limit is 55 MPH if I recall correctly. I drop to 5th and settle between 1900-2000 RPM and 55 MPH. Almost instantly my water temp drops to 190* or less and shortly later the tranny temps drop to about 193-195*. I have enough reserve to suffer minor slow downs without downshifting again but if I get below 50 MPH (around 1800 RPM) and it looks like it could get worse, I down shift to 4th.

The only thing I don't have, but want, is an exhaust gas temp gauge. I want one.

That is MY technique and serves me well. Some folks think the tranny is smarter than the driver and let the tranny do all the thinking. That is not my choice. YMMV. Besides, I'm an anal retentive, control freak.

[dstinch]

6 plus grades for mine (350 cat 36 journey) 35 to 37 mph is normal and 2300-2400 rpms. It will start shutting down at 2500rpms. 40,000 miles so far. Lots of miles in Idaho,Montana,Wy.

Don