victorber

I have had my MDX for about 3+ weeks and have 920 miles on her. Problem I think I have is I can not see a drop in the RPM at a steady speed showing the ACMS is engageding. On my RLX I would feel the ACMS engage and see the corresponding drop of the RPM.
I may be having a problem understanding how the ACMS operates in the MDX?

Can anyone shed some light on weather I have a problem or a misunderstanding of the systems operation?????

TIA

rcy

What is ACMS? Are you referring to the variable cylinder management? The RPMs shouldn't change when VCM is active as the engine is turning at the same speed - it's only that 3 cylinders stop receiving gas.

If you have the instant fuel economy displayed, you can see it drop substantially when the VCM kicks in - that's how I can see it's active.

victorber

Ok, The VCM System is what I am trying to understand, in cruise at 70mph in the RLX I would definably see both a drop in RPM and see the gas range increase, I would always feel the like a change in a gear as in 4th to 5th....
I can't find anything in the Owners Manual on the system operation....

rcy

I could be wrong about the rpm not changing then, but I don't notice it on my 14 MDX. I do notice the instant fuel economy dropping considerably. I'll have to look closer next time I'm cruising on the highway.

victorber

Thinking back, I am trying to put together on my 80,000+ miles in 21/2 years of travels exactly the how things occurred.....
I only wish I could read up on the system integration and operation???????

Worst part of getting old'r...

rcy

I've always wondered why Acura doesn't have some sort of indicator in the dash to show when VCM is active. It would make it easier to tailor one's driving to gain the most fuel economy.

E92Vancouver

VCM is seamless. You won't notice a thing.

Dimcorner

Shutting down a few cylinders would not affect your RPM at all. If your speed and gear are the same then your RPM would not change whether no matter how many cylinders you are firing.

victorber

Thanks to all for your replies, now I have about 1450 miles and the system seems seamless in it operation...