I am debating on adding a normally close contactor or relay to the positive side circuit to the fuel injectors. I would like to shut off cylinders 1,3,7 and 8 while I am on the interstate to gain better fuel mileage. Would I possibly hurt the engine or cause damage? After looking at the firing order I think the motor will remain balanced.

Will I damage anything by doing that?

Thanks

 

It would take WAY TOO LONG to recover your costs. You'll have to figure out how to close the valves on those cylinders as well as all the other things MDS does. I don't think you'd ever come close to recovering the cost with the meager fuel saving. MDS turns off 3,5,2 and 8 I think.

 

Yeah...... That plan ain't gonna be a good one.. displacement isn't your issue per say anyway.. its but one way to address economy, and adjustable displacement is dang difficult on an engine not specifically designed for it..

Alter your approach.. focus on eliminating unwarranted engine load.. and alter your driving habits.. between those two, plus keeping the engine in good tune, you're not going to get much better, even if you had MDS...

 

Everyone with MDS buys a tunner to turn it off and your trying to modify it to come on a truck not equiped with it. Like they said if you did get it to work you wouldnt see any real gains. And the MDS controls the shutdown between 2-4 cylinders at a time depending on what terrain your on when you dont have your foot in the gas. Not just 4 automatically thus leaving you with worse fuel eco than you started with
MDS was a great idea for places like CA with big time emissions controls but was a terrible idea to try to move a tank with 4 cylinders.

 

Not a good idea, the cylinders wouldn't be rotated. Start with an e-fan, parasitic loss is what you are after, plus driving habits, like was said above, You also might consider tires that have a low rolling resistence at your next tire change, etc, etc, or--buy a used prius for work, and jam in the truck on the weekend.

 

Efan Low, temp thermostat, Better Air Filter(One that Breathes more than the 15 dollar paper POS) Those are all things that will free up some HP and Acheive better MPGs just remember your truck weighs 5000+ pounds Good Mpgs are hard to come by.

 

It was just a thought, I wasnt sure how the MDS worked. What about a chip? Just saw an add for a "G Force" chip that gains 60HP and sumtn sumtn torque and claiming to add 4 - 7 MPG???? I am used to diesels and I have no idea on gas motors.

 

Snake oil...
Call me crazy, but what if the op took the pcm and harness from a MDS equipped truck and put it in his....
Don't kill me....just an idea..

 

Wouldn't work. If you want mds, trade the 04 in and get an 06.

 

I would strongly recommend staying away from these so-called 'performance' chips. There are lots of posts on this and other forums about them. Many items show up in the search results. There is no way a $60 'chip' is going to net you 60HP and 4-7 MPG. Most likely, you wouldn't even be able to tell a difference.