Whats happening fellaz? Gonna try and make this as short as possible. Got 2 seperate convos with both of my trucks.

Ram- Cleaned the TB, swapped the plugs (champion coppers), changed the oil to full synthetic (Castrol), took the 'tube' off the stock air box (crappy DIY intake with K&N drop in). Filled her up, reset the odo. and overhead. Got less than 250miles on a 26gallon tank, running it down as far as I could go (I know I know, not a good idea). Plus the idle is weird sometimes, drops to 500rpms, and slightly acts like it wants to cut out, like it has cams. (I wish ) The overhead is reading 9.3-9.5, which isn't too far off.

'Rango- Cleaned that TB too. Since, the idle is crazy, sometimes jumps up to 1500+rpms, then it settles down after a sec or 2. Plus the MPG's have gone from 12.5ish to barely 200miles per 24gallon tank, maybe slightly over 200miles. Im assuming the idle is due to the IAC, maybe, but the mpg's getting that much worse after a TB cleaning is kinda weird. I KNOW it needs new plugs and such, but dayum. I didn't think the cleaning would hurt anything.

Sorry for the long read. It's just kinda weird that the little maintaince that I have done has made things worse. Just wanted to present this to the jury, see what the verdict(s) might be. Thanks buddies.

 

my guess is that you effed up the IAT sensor... or it could be EGR valve? does the 4.7 have one? IDK...
run some lucas injector cleaner through a couple tanks in both... it got rid of my stumble...
otherwise IDK... would like to see what everyone else says...
do you have air in the tires? parking brakes arent on?

 

Lol, yea, air is in there, although I do need to check it, they just got put on about 500miles ago, no telling what the shop has in there. I know the bigger treads and slight higher stance of the level isn't helping, but I was figuring that the maintaince I was doing would keep it up to par with what it was before the tires/level, which was still only 11ish mpg's.

 

Well, anytime you put bigger tires on and raise the truck into the air, you're gonna get worse mpg's most definitely. My guess is since you put the larger tires on you didn't notice you're mpg's went down, only after you did a tune up did you really pay attention. You could also try recalibrating your TPS.

https://dodgeforum.com/forum/3rd-gen...procedure.html

You could also try resetting the pcm and see if maybe the computer was "used" to the dirty throttle bodies.

 

When I did plugs on my Ram i think it got worse mpg's as well. I am too cheap to buy another set of plugs and do it again. And mine has the same weird idle as yours. and I get 243 a tank.

 

That's weird. I got better mpg's. Did you make sure you gaped the plugs to the correct spec?

 

I gapped them to .40, which is what those particular plugs called for (I thought I'd read that our 4-7's called for .44, so IDK).

That little intake tube being taken off wouldnt have anything to do with the mpg's would it? I highly doubt it, just a thought. Maybe Ill throw it back on for the next tank, see what'll happen. I'll try the other tricks you suggested Jon, I just hate doing resetting the PCM cause I have to go back and re-adjust the million settings this "fancy" headunit has. Anything 's wortha shot though, I'll just go through and write all the settings down before hand

Hows bout that Hemi, any ideas on that one? Thats bugging me too. I know the wife isn't hard on it, and I don't drive it enough to have that much affect on it......

 

After reading that procedure Jon, is this even for the 4-7's? To show how little I know, Ill ask this question (): Since the Hemi's are electronically throttled, and the 4-7's are fly-by-wire still, would they both have a TPS? I know that means "Throttle Positioning Sensor", but not entirely sure what it is/does/means beyond that, so thats why I ask this. Im going out of town next week for work, so I'll do both tricks to both vehicles when I get back, see what happens.

Thanks guys!

 

your mpg's were prob already in the shltter u just didnt kno because u hadnt reset the mpg on your overhead in a while. lets say you hadnt reset it in 10k miles. then something goes wrong, now your getting bad mpg's for 1k miles. the over head isnt gonna change because the average mpg is still the same even with the mileage your currently getting. i bet if u hadnt reset the overhead you would have noticed a very very slow decrease in mpg as the average evened out.

 

I instantly saw worse mileage on the overhead and the odo after the tireswap, even before I reset everything for the fulltank calcs. It went from 11.5-12 down to 10.5 after the first 100 miles or so with the new treads. Thats where the extra kick-n-the-azz came from to do the plugs, trying to at least get back up to where it was.

But like I said, I don't put too much faith in the overhead. I just reset both to kinda compare the two. Hand calculations say Im getting 9.5-9.6 per gallon. Thats freakin horrible! Lol, not worth the couple extra inches in tires and 1.5in in "lift". I know I have a truck and all that jazz, but the 12 I was getting (on a good day) was pretty bad in itself, much less what Im getting now. Maybe when summer comes 'round and the 'better gas' starts coming in, things will change. I guess now a gearswap is on the horizon, maybe it will help the lil ol 4-7 out some.....

Damn I just went on a lil rant, sorry. Lol, I just now did the calcs while typing this, made me damn near sick!! I kinda wish I had that lil 87 Accord back now, Ugly, Slow, I barely fit, but that 30+mpg was nice (in addition to the Ram of course, it'll take more than this for me to give'er up!)