2012 - Decreased power on incline

[Rover Range]

Meant to add, I am not towing or have any added weight besides my prospeed rack and rock sliders. They have been on since purchase, so it is nothing new from an added weight standpoint.

The vehicle learns how you drive. It's called Adaptive Strategies. "
You can disconnect the battery for 30min. This will reset the learned adaptions.
See if this works.

 

[Al Pizzica]

Next time this happens put the vehicle in "sand" mode. The one with the cactus. If it doesn't leap up the hill like a scalded cat, something is indeed wrong.
Tranny had a service yet? First symptom I noticed when the fluid got old was reluctance to downshift and a clunk when it did.

 

[jlglr4]

Possibly a brake dragging? Might check the temp on your wheels, see if any are hotter than the others?

 

[Neil Couvillion]

It doesn't at all feel like a brake issue and is not more prevalent now in general driving on flat ground, but most noticeably on any incline. I am getting it fully diagnosed by my specialty LR shop tomorrow and will update the group. Hopeful it is just general transmission service, but with a rover, I always think the worst. Cleaned sensor, and it still does it.

 

[powershift]

The bands in the tranny might be slipping.

 

[Neil Couvillion]

So, both my Indy shop and his recommended transmission shop are unsure what is going on. We changed the fluid and added anti-shudder additive. I am giving it 50 miles to see if things change & get better. Fingers crossed. Still no codes.

Thanks for your input.

 

[Al Pizzica]

I still don't understand this one. If you floor it from a stop up a hill what exactly happens? If nothing is slipping (slipping=engine revving but vehicle not moving any faster) then either it is choosing too high of a gear (shifting to manual and holding first to near redline can test this) or there it is something wrong with the throttle mapping (sand mode gives highest gain throttle mapping i.e. pushing the gas less opens the throttle more).
What you describe is like when I forget it's in snow mode after the snow ends: it chooses way too high a gear and goes to lowest gain throttle mapping)

 

[Neil Couvillion]

Me either. If I start at an incline and hit the gas, rpms just stay constant, even when I floor it. I think it is starting in a higher gear b/c nothing feels to be slipping. I had to travel the day after I got it back so I have not tested the manual transmission on the incline and will do that this weekend. I will send a video as well. Thanks for your input and thoughts.

 

[jlglr4]

I wonder if you’ve got a weak fuel pump that can’t keep up with the increasing demand under load.

If you have a gap tool, you could monitor your fuel rail pressure and demanded rail pressure when driving and then climbing a hill. Actual pressure and demanded pressure should stay pretty well aligned. If demanded pressure is signficantly higher, that suggests a fuel supply issue.

A weak pump also should show up in fuel trims, certainly with load but maybe even without. With a weak fuel pump, fuel trims should show increasingly positive trim as rpm or load increases. If you check fuel trim, make sure to look at both short and long term trims and add the two together to get overall trim data. Might start with checking trims while stationary (in neutral or park) at idle, 1500 rpms, and 2500 rpms to see what it looks like. Monitoring fuel trims while driving is a bit tricky because the short term trim is always bouncing around.

Note that these tests won’t tell you whether the problem is the high pressure or low pressure pumps, but might point you in the direction of a fuel supply issue.

 

[jlglr4]

One other thing (at the risk of stating the obvious) - make sure the air filters are clean. I guess that makes me think also of cleaning/testing the mafs. But I’d still look at fuel pressure/trims first if it were me.