That is all I have ever put in it. I think I will try a oil system cleanout before I do anything else. (I still want to turn mds off though) Superchip flash tuner is on the way. Are there any techs that can confirm or deny my idea that if I turn the mds off the miss should go away?

 

When does it miss? Is it only in situations when the MDS can kick in (ie, light cruising)? If that's the case then it's probably the MDS and turning the MDS off will probably fix it. Try this, next time it misses, floor it, if it stops missing then, to me, that confirms that it's the lifters, cause when you floor it MDS kicks out. Maybe I'm wrong but it makes sense to me.

 

You can also just drive around for a while with tow/haul on, if I'm not mistaken this disables MDS, that should tell you...

 

You are right on Hammer only when I floor it and the mds is supposed to kick off it doesn't. The lifter sticks and holds the valve open. I found a superchip flashpaq today in town, and grabbed it. (cancelled my online order) loaded the tow setting and turned mds off. I may load another setting (87 or 93) when my gas runs out. I just put $20 dollars worth of 89 in it. The miss is gone for now and only time will tell if it is gone for good.

BTW, there is definitely a noticeable difference after the flash.

 

You should be running 91 or higher octane for the tow tune - as per Superchips. But honestly I don't know why. Timing isn't advanced nearly as much as the performance tune. Just a FYI.

I'd either run the 87 tune with the 89 that's in the tank, it's still a good bump over stock settings OR I'd hit that 89 with some 93 at half a tank to get the octane up to 91. Another FYI, I've found the best gas mileage is with the performance tune, enough so that it justifies the added cost of 93 octane over 89...

 

O really??? I would expect mpg to be about the same with or without the mds, but not the 91 tune vs the mileage xs. Many thanks for the info. And help. I will find out with the cold start in the morning weather or not the miss will come back.

 

Man i don't care what gas we put in the wife's truck. I got a heavy foot and the 5.7 hemi just suck's it down.

 

If it comes back at all you can pour 1/3 can of seafoam in the crank case and the rest in your gas tank(along with a full tank of 93) and drive it for about 40 miles. Then change your oil right after. Should help unstick the lifters without replacement.

 

So far so good but havent had a cold morning yet. I may go ahead with the seafoam and oil change anyway. Either that or Marval. is seafoam recomended over Marval mystery oil?

 

If I end up breaking this engine down I will need a lot of advice from y'all. Theres no way I will go that deep into the engine and still have a smooth idle when I put it back together. BTW I have wanted a new exhaust for a long time, has anyone installed a Borla over a Flowmaster?