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  #13  
Old 08-07-2011, 11:58 AM
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Re: now i have mds issues

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Originally Posted by jeep5.7 View Post
ok...so i changed my plugs,went great,still is,big difference in power and mpg,but...my 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
Have the same issues.....when it works at all.
1. Here's more MDS theory: http://www.wkjeeps.com/wk_engines.htm#MDS
2. Champion 570's are the equivalent of the MOPAR OEM factory spark plugs. The MOPAR number was also on the Champion box under the 570 number. Had both installed in mine and no discernable difference.
3. There is a TSB for 5.7L driveability. Has yours been done? ( http://www.wkjeeps.com/tsb/tsb_wk_1800610b.pdf )
4. Xmission does not necessarily lock up in MDS mode. It can float up or down as necessary. (Had the same question and service manager told me that.)
5. At one time, my MDS was in-and-out 8 times per mile at 70mph on flat interstate highway. Looked more like a turn signal....... Now it works 50% of the time or less. Not sure if this is an improvement or not, but the mpg's on the DashDAQ XL read more accurately when it doesn't.
6. MDS behavior seems better with 89 octane fuel than 87, but only slightly so.
7. How is your EGR valve? I had many of these symptoms until it was changed. The EGR valves seem to be shot by 50K miles, but it does not show up on the maintenance radar, except on the WK forums.
8. The throttle body should be cleaned periodically. The back side of the body and the back side / edges of the butterfly get coated with oily crud from the PCV valve discharge and EGR tubing that enter the intake manifold (RHS front) just behind the throttle body butterfly. This is a low pressure area and the swirling makes it a perfect plate-out point. Use soft clean cotton cloth (old T-shirt) and isopropyl alcohol to wipe off carefully.
9. Verify your PCV valve is free. Remove and shake it. If it rattles, it's suitable for continued service.
10. Check the emissions hose connection and crankcase air intake hose connection on the LHS front of the intake manifold. Easy to knock off when changing plugs.

My experience and 2 cents worth.......... May be worth what you paid to get it.
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  #14  
Old 08-07-2011, 12:22 PM
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Re: now i have mds issues

thanks walt im gonna go outside and check my hoses now,and i should look into that tsb
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  #15  
Old 08-07-2011, 01:36 PM
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Re: now i have mds issues

Seriously - change your EGR - I think it as WALT earlier talking about the ole shake it & it's good. Mine was good by that theroy too. I dont know but I think our jeeps are much more sensitive to the EGR.

My JEEP was acting wacky all kinds of different things. I changed the EGR - It rattled too.My check engine light came on for about 30 minutes of driving then went off not to return again. I checked the code and it was the P0406. I went ahead and changed the EGR anyway and it made all the difference in the world.

Quick question... HOW do you know when the MSD is kicking in and out? Is it something you feel?
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  #16  
Old 08-07-2011, 02:25 PM
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Re: now i have mds issues

Now i have it easier since the 08s come with a FUEL SAVING light when MDS is on, but you can see and feel when it kicks in. Watch the tach when you are on the highway, give it some throttle and you are in 8 cylinders, then back off almost completely and watch the RPMs jump UP about 200-300 RPMs. When it jumps UP MDS is on, when it jumps back DOWN MDS is off and you are using all 8 cylinders.

When cruising slower on backroads roll down the window and you can hear it when its on. Sounds like a gurgling diesel when MDS is activated. Even my wife noticed it, which is saying a lot! haha
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Old 08-07-2011, 06:25 PM
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Re: now i have mds issues

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Originally Posted by jeep5.7 View Post
wow thanks alot viking
No problem, let me know if you have any other issues!
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  #18  
Old 08-07-2011, 08:27 PM
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Re: now i have mds issues

exactally what hemi 57 said jwer,on the evic it comes on and off,and you can actually feel it
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  #19  
Old 08-07-2011, 09:51 PM
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Re: now i have mds issues

Us 2005 guys aren't lucky we dont have a fuel saver light when MDS turns on...BUT if you have an aftermarket exhaust there is a noticeable change in exhaust tone when it turns on too.
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Old 08-08-2011, 05:18 PM
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Re: now i have mds issues

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Originally Posted by viking757 View Post
Us 2005 guys aren't lucky we dont have a fuel saver light when MDS turns on....
jeepgcoman developed a simple MDS activation light for you guys without the EVIC display. Use the search function here and other WK forums. Also read at the end of this section: http://www.wkjeeps.com/wk_engines.htm#MDS

Install it and you will know for sure. After a while, you will recognize when MDS activates. However, it should be relatively smooth, especially after the TSB flash.
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Old 08-08-2011, 08:22 PM
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Re: now i have mds issues

You'll find my original install procedures that I did back in 05 for the LX vehicles on the LX forums in the following thread: http://jeepgarage.org/showthread.php?t=11299 , Post No. 6. You can also see where I mounted mine. As I said, the wiring is exactly the same. The WK is actually easier because there is a firewall pass through right behind the PCM/TCM on the WK. I pulled the glovebox and routed the wires up to where I wanted the light. Very easy install compared to the LX.
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Old 08-08-2011, 10:44 PM
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Re: now i have mds issues

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Originally Posted by jeepgcoman View Post
You'll find my original install procedures that I did back in 05 for the LX vehicles on the LX forums in the following thread: http://jeepgarage.org/showthread.php?t=11299 , Post No. 6. You can also see where I mounted mine. As I said, the wiring is exactly the same. The WK is actually easier because there is a firewall pass through right behind the PCM/TCM on the WK. I pulled the glovebox and routed the wires up to where I wanted the light. Very easy install compared to the LX.
Thats a really good idea. Thank you!
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Old 09-27-2011, 07:12 AM
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Re: now i have mds issues

Quote:
Originally Posted by jwernatl View Post
Seriously - change your EGR - I think it as WALT earlier talking about the ole shake it & it's good. Mine was good by that theroy too. I dont know but I think our jeeps are much more sensitive to the EGR.

My JEEP was acting wacky all kinds of different things. I changed the EGR - It rattled too.My check engine light came on for about 30 minutes of driving then went off not to return again. I checked the code and it was the P0406. I went ahead and changed the EGR anyway and it made all the difference in the world.

Quick question... HOW do you know when the MSD is kicking in and out? Is it something you feel?

You are confusing the PCV valve with the EGR; i.e., if it rattles, means the valve is OK. Which did you change, the PCV or the EGR, as it takes a minute to do a PCV.
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  #24  
Old 10-07-2011, 12:59 PM
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Re: now i have mds issues

what every one is saying is great stuff that will help alot. my 09 w/ 22000 miles started to act a little funny. mil light turned on then off again for 2 day, i tried to pull codes and i cam up empty... i took it to the dealer and it turns out the fuel in alaska is shit.... extremely dirty even 91 oct ect.... i run fuel treatment ect. and still had the problem. they disconnected the fuel rail from the injectors and ran a really some treatment through my engine... from my understanding is a pressurized bottle of extreamly toxic shit shit that clears all the junk out of it... its running great MDS kicks on perfectly.... could be part of the problem???
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