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jeep5.7 08-06-2011 09:49 PM

now i have mds issues i changed my plugs,went great,still is,big difference in power and mpg, mds is acting funny,it comes on at about 15-20mph and its fine through 30-50mph but when im at highway speeds it seems to be coming on and off a real lot,more than it did before and it hits hard and kicks off hard,and there seems to be alot drag when its on,then when it deactivates the rpms jumo a few hundred rpm,please help,it was fine before,and i used the 570 plugs and gapped them at .45

viking757 08-06-2011 09:51 PM

Re: now i have mds issues
My guess is if you unplugged the battery when you did the plugs the computer is going to take a few to relearn your driving habits.

lll2for3lll 08-06-2011 09:52 PM

Re: now i have mds issues
What engine oil are you using?

Chaoul1 08-06-2011 09:54 PM

Re: now i have mds issues
X2 one both of those questions. Make sure you are using 5W20!!!

jeep5.7 08-06-2011 09:54 PM

Re: now i have mds issues
i tried valvoline,freakin hate it,never again,but it was fine before i changed them,5-20 by the way,can i switch to a synthetic at 54,000

jeep5.7 08-06-2011 09:56 PM

Re: now i have mds issues
it seemed fine ,i drove for about 5-600 mi before it started and i did take the neg off

lll2for3lll 08-06-2011 10:08 PM

Re: now i have mds issues
Use Mopar oil.

jeep5.7 08-06-2011 10:13 PM

Re: now i have mds issues
mopar oil???what at the dealer?

lll2for3lll 08-06-2011 10:20 PM

Re: now i have mds issues
Yeah. Mobile Engine Oil.

viking757 08-06-2011 10:37 PM

Re: now i have mds issues
Im telling you dont worry if you have no DTC's its just the computer relearning everything. As for oil I doubt thats the cause since you are using the correct weight and it worked fine prior. If you are really worried there was an MDS calibration procedure that isnt used anymore but wont hurt to give it a shot.

MDS Reset & Calibration

1) You need a fairly long, open, safe, straight road for a WOT run to about 35 mph.
2) Get engine up to operating temp, engine running and car stopped place gear selector in "[D]". Bump it to the Left until in "[1]".
3) Turn off all electrical accessories (except lights if needed).
4) Make a WOT run to 4500 RPM (about 35 mph), immediately remove foot from accelerator and do not depress the brake, let the vehicle coast with the throttle closed until the vehicle speed is again at 35 mph or lower.
5) Stop vehicle and place in "Park", verify all instrument cluster warning indicators are off.
6) Cycle ignition switch "Off" and back "On", but do not immediately start engine.
7) Hook up StarScan and clear DTC's (only necessary if you have any dtc's)
8) MDS calibration is now complete.

jeep5.7 08-07-2011 07:49 AM

Re: now i have mds issues
wow thanks alot viking

Chaoul1 08-07-2011 07:53 AM

Re: now i have mds issues
You can use any 5W20. Also you can switch to Synthetic whenever. I use Mobile 1 Extended Performance 5W20. I love it. I just prefer Synthetic since you can run it longer. But I still do my Oil Changes every 3,000 Miles.

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