Jump to content
Mopar1973Man.Com LLC
  • Welcome To Mopar1973Man.Com LLC

    We are a privately owned support forum for the Dodge Ram Cummins Diesels. All information is free to read for everyone. To interact or ask questions you must have a subscription plan to enable all other features beyond reading. Please go over to the Subscription Page and pick out a plan that fits you best. At any time you wish to cancel the subscription please go back over to the Subscription Page and hit the Cancel button and your subscription will be stopped. All subscriptions are auto-renewing. 

New revised MPG/High idle switch design


Recommended Posts

In 3 cylinder high idle, the truck ramps up to 1200 rpm on all cylinders and then the ecm cuts fuel to 3 cylinders. This forces the remaining cylinders to "drag" the "dead" cylinders. It essentially is forcing the engine to work, and work creates heat. This is a software program directly from Dodge, you don't need the mpg fooler to utilize this. Either someone with a Smarty can enable it or the dealer can flash your truck if it hasn't already been done. What the fooler does is give you control of when you want to use it. Sent from my DROID4 using Tapatalk

Link to comment
Share on other sites

In 3 cylinder high idle, the truck ramps up to 1200 rpm on all cylinders and then the ecm cuts fuel to 3 cylinders. This forces the remaining cylinders to "drag" the "dead" cylinders. It essentially is forcing the engine to work, and work creates heat. This is a software program directly from Dodge, you don't need the mpg fooler to utilize this. Either someone with a Smarty can enable it or the dealer can flash your truck if it hasn't already been done. What the fooler does is give you control of when you want to use it. Sent from my DROID4 using Tapatalk

That's pretty cool. Thanks for the explanation. So, for example if the dealer flashes my truck, how then does the high idle activate? Does it come on automatically somehow? Or Do you actually need a smarty or the fooler to truly be able to activate a high idle?
Link to comment
Share on other sites

No Smarty needed, however if you know someone that has one they can activate it for you without going to the dealer. I forget the temps needed to activate the high idle and 3 cylinder high idle but it is in the ballpark of the low 20s and low teens for each. The IAT sensor has to read this so it actuallh has to be colder ambient temps. Also if your truck has been plugged in the temp registered by the coolant sensor will override the high idle features. This is where something like the fooler is nice because you can activate it whenever you want regardless of temps.Sent from my DROID4 using Tapatalk

  • Like 1
Link to comment
Share on other sites

I don't know of any single add on that will net a 6 mpg increase.....now that i think about it I dont know that you could do much of anything to net an increase of 6 mpg above the manufacturers ratings short of cutting the body off and throwing it in the scrap pile.Sent from my DROID4 using Tapatalk

Link to comment
Share on other sites

During the wintertime, you lose mileage. It's due to the ECU getting a cold air reading from the Intake Air Temperature sender & changing the injection timing. People tend to lose 4-6 MPG. Mopar1973man has the stats on that. The MPG fooler tells the ECU it's a nice sunny 85* day out.Ed

Link to comment
Share on other sites

I understand how they work I've got a simpler version I've been running for 2 solid winters now. I mainly wanted the ability to use the 3 cylinder idle on cold mornings. Its dang hard to get the equivalent of summertime mpgs in the dead of winter with the flip of a switch. Yes you've fooled the IAT into thinking it's seeing the higher intake temps and altered the timing a hair. Now what about that cold dense air your sucking in and all the fluids that are at a much thicker viscosity due to the frigid temps. It takes several miles just to get everything warmed up and to temp, sometimes as much as 10 to 15 miles depending on driving conditions and temps. And this is assuming the roads are dry, if theyre snow covered there goes everything you may have gained. All these factors suck the fuel mileage right out the tail pipe. I am in no way knocking the system I believe it does help but if everyone expects to gain 6mpg by buying one of these there are going to be some disappointed people. Everyone will see different gains, my real word numbers are +1 to 2 mpg difference in the winter vs running with unaltered IAT values.Sent from my DROID4 using Tapatalk

Link to comment
Share on other sites

I am in no way knocking the system I believe it does help but if everyone expects to gain 6mpg by buying one of these there are going to be some disappointed people. Everyone will see different gains, my real word numbers are +1 to 2 mpg difference. Sent from my DROID4 using Tapatalk

That's the most I have lost too. Not even close to 6 MPG. Using the hot start it is much closer to 1 MPG.
Link to comment
Share on other sites

I have the home made IAT fooler on a switch on my knee panel. In cold weather, I don't like how the truck starts w/o the grid heaters, so I leave the IAT fooler off, until the engine starts & then turn the IAT fooler on. In either case, I think the IAT is worth about 1 mpg. I intended to test other resistors than the 143* one of the initial set up but never got back to it. I also have a Quadzilla. I generally leave it in the +30hp/econo mode. I get crisper shifts & is much more drivable this way. This is worth about another 1 mpg. I intended to try out other tunes for the +65hp mode but it ran good with the original tune now with Quadzilla out of business, I decided to not monkey with a going machine. It is just enough to pull hills with my ToyHauler on without excessive down shifting. As far as I know, I don't have high idle enabled. I've never had a reflash. That's it.*Note my sig... I have 4.10 gears

Link to comment
Share on other sites

As said, I am sure Michael will chime in with real numbers. We all know his penchant for writing it all down. Winter fronts, warm air intake, optimal tuning & driving for mileage all lead to better mileage with the fooler.

If I am wrong, I will gladly retract my statement. But, I figured it at 3MPG recovery at 3500 miles at $4 a gallon & it came out even. As with any mod, your mileage will vary due to different mods & driving styles.

Ed

- - - Updated - - -

OK, I talked to Michael. You all are correct about 1-2 MPG gain with the fooler. Sorry for the false advertising. I musta been thinking about one of his combo threads with those numbers. Might have beem tire/fooler/headwind, if I remember right, now...

Again, sorry,

Ed

  • Like 1
Link to comment
Share on other sites

I have seen write-ups for modifying the IAT - where 3 DPDT switches were used but where a 4 position switch would work nicely (normal-use IAT, substitute a resistor for 143°. substitute a resistor for about 35°, and substitute a resistor for about 10° ...2nd position gives MPG improvement, 3rd gives high-idle, and 4th gives the high idle + 3 cylinder ops.) I have seen write-ups for modifying the ECT - substituting a 3.3K resistor to simulate very cold conditions....but the write-up isn't quite specific as to whether or not the ECT low-temp fake is required for high-idle or high-idle+3 cylinder ops.A question for Yankneck696- Does the new design switch off the ECT sensor and substitute a resistor for the 3rd or 4th or both positions on the rotatable switch? Is the ECT 'fake-out' even required to get high idle or high-idle+ 3cylinder ops?Thanks

Link to comment
Share on other sites

As far as I know, the set up you described at first in your post is exactly what this new design does. It is a 4 position switch. You get your normal IAT mode, MPG mode, 6 cylinder high idle, and 3 cylinder high idle. You don't need to do anything with the ECT sensor if I am not mistaken.

Link to comment
Share on other sites

When left in the 6 cylinder high idle, the ECT fooler resistor is engaged too. That allows you to keep the 6 cylinder feature on indefinitely for better charging & extended times of heat or AC. Mopar1973man designed it that way for when he was responding to fires & accidents to keep the alternator charging good while his lights are on. This feature has been stress tested on a truck with 6X13 injectors & didn't have a problem with overheating at all & EGTs were very safe.Ed

  • Like 1
Link to comment
Share on other sites

YEY!!!!! I have been WAY TOO busy trying to address a number of issues to have a chance to look at who was building these fooler boxes now... and I couldn't be more happy that I came across this posting tonight!!! Ok seriously I have to fix a few more things before I will be ready to install one... like fixing the mess my husband created by driving the truck when I explicitly told him NOT TO!!! SO FRUSTRATING, I hope that none of your wives do that... although honestly I am tired of the dynamic created by society that says if a couple owns a truck than it must belong to the husband. Please excuse my ranting, I am dealing with a mechanically inept spouse who thinks that taking the vehicles into grease monkey will be a better option than actually observing your vehicles performance and associated noises... honestly I think that if the mechanic told him he needed to change his headlight fluid he would be like, OH... Can you do that now? But you also have to understand I am not a man hater at all... I am just a little grumpy because I broke my leg in 8 places (tib and fib), had surgery 8 weeks ago and still am not allowed to put weight on it, and yet I am the one under the truck for the past week trying to lower the fuel tank by myself (so I can finally get that pesky Air Dog and draw straw installed) not to mention fixing the busted brake line that my husband caused which would have been easy to replace however when I asked for his assistance in bleeding the brakes he sheered off not one but both rear bleeder valves... which he then proceeded to try and quickly fix with an easy out that he broke off as well... three trips to the part store later and a lecture on the way about "this is why we need to just take it to a shop..." I am a little more than FURIOUS! to help paint the picture, I will break the taboo and share that I am roughly 5'8" and just weighed in at 125lbs.. I have lost some muscle with this damn broken leg and being in a cast/ now walking boot for 9 weeks.. so rolling around under a truck is a little tricky right now with only one leg that I can use to manuver and use for leverage with trying to break thing loose and tighten them back up...BUT, when I saw this new switch it made me smile!!! I will definitely be ordering one after I get the rest of the parts I already have installed... Which will hopefully be sometime in the next week... (as long as I don't have any help from my husband I should be fine)... My only lesson that I have learned is this... We honestly need a really simplified operation manual for these trucks and all the nifty aftermarket parts we install in them... I would love to ban my husband from driving the truck entirely however that has caused a giant riff in our household... so I have been trying to come up with a solution... for instance creating a very short and maybe slightly over dramatic write up about why it is important to be an observant operator of the vehicle... example... fuel pressure is important, if the pressure drops and the truck continues to be driven you can cause THOUSANDS of dollars of damage.... This has gotten off topic now and has turned into a manifesto... not my intention at all... but here is the point that I would like to make... THIS SWITCH with engraved labeling and LED light are great for people like me who unfortunately have other people who occasionally drive our trucks even when asked not to... For people like us a VERY simple half or quarter page tutorial and explanation that includes consequences of not following the directions would be very helpful... the best parts in the world are only as good as the user... unfortunately...THANK YOU ALL for taking the time to design and implement this for all of us that live in the blustery cold winter areas... Sarah

Link to comment
Share on other sites

I built my own IAT fooler out of parts following the discussion here. Thanks guys! But I had to source the pile of parts, solder them up, insulate the joints, harness everything before I could install. And this's just the IAT part. It works like a charm. Having a kit will be preferable by far & will open this upgrade to many more people.A lot of time & effort planning the build.Fair amount of time sourcing components, ordering, sending back, getting right parts, trips to Radio Shack.A lot of time & effort doing the build.A PITA getting to the plug on the back of the engine.Finding an open grommet & running the wires wasn't too bad.Drilling a hole in a perfectly good dash... scary!

Link to comment
Share on other sites

When left in the 6 cylinder high idle, the ECT fooler resistor is engaged too. That allows you to keep the 6 cylinder feature on indefinitely for better charging & extended times of heat or AC. Mopar1973man designed it that way for when he was responding to fires & accidents to keep the alternator charging good while his lights are on. This feature has been stress tested on a truck with 6X13 injectors & didn't have a problem with overheating at all & EGTs were very safe. Ed

Thanks for straightening me out here. I didn't realize the high idle wouldn't stay engaged if the ECT wasn't fooled as well. Learn something new everyday I suppose..
Link to comment
Share on other sites

×
×
  • Create New...