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Discussion Starter #21
My issue is still real....anyone have new ideas aside from replacing the lifters back to MDS or installing a NON MDS Cam?
 

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I have been reading about the problem using MDS Cam with NON MDS Hellcat lifters with a misfire at idle only on the MDS Cylinders. I have been having the same problem in a 6.4 Jeep. Did you end up solving the problem without changing Cam or Lifters? If so, i would appreciate any information. Thanks.
 

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You can use the stock camshaft still, the Ram 1500 cam is unique to the Ram 1500; one from a 2500 requires a tune and has less peak output with a broader curve. The Challenger manual transmission cam and the cam in the Durango/GC/Charger/Challenger auto etc... are also different. The only MDS specific feature to the camshaft is a preload ramp built into the lobe profile to help take slack out of the deactivated lifters. Running it with non-MDS lifters won't make a difference.

Just FWIW, I know people like to blame MDS for this but it happens to 2500s with the 5.7 too, which don't have MDS. On MDS engines it happens to both MDS and non MDS lobes. Just sayin'

Some guys go with Hellcat lifters-they fit
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I know for the OEM parts the yokes are a different part number from lifter sets; each bank has a front and rear set, each set has 4 lifters held by 1 yoke, and each bank has one of each set-there are not separate ones for front right, front left, back left, and back right.

MDS solenoids can throw a CEL if a fault is detected in them, but if MDS is tuned off it shouldn't matter; you don't need to run block plugs and can just leave the solenoids as place fillers in the closed position.

I did find a photo of an MDS ad non-MDS lifter but can't post it here because we can't link to other forums. The top of the MDS lifter is tapered and the top of the non-MDS lifter is squared. If an MDS yoke was used (each yoke contains both MDS and non-MDS lifters) with non-MDS lifters then the squared part at the top of the lifter would not fit into the yoke all the way and maybe the cam was lifting the valve open slightly because the lifter wasn't sated right.

It could be any number of things, but I suspect there was a problem with how it went back together
So can I simply remove the MDS solenoids replace the lifters with non MDS lifters and ride without a tuner?
 

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So I can replace the MDS lifters with non MDS lifters remove the MDS solenoids and use the factory Cam and I shouldn't need a tuner correct?
 

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Hello hemi fans,
I own a'12 Challenger 5.7. With 130,000 relatively trouble free miles out now developed a misfire on cyl. 5. Mds which always worked like it should now seems disabled due to the c.e.l. that's on. Strange that it still has power and good drivability, except for a for a rough idle. Was going to pull thre head off and take out the suspect lifter but haven't had thre time . I did pull valve cover and observed thre rocker arm for#5 intake wasn't moving. I hoping it's not the dreaded worn down cam lobe.
Nice to bree a member... my son drives a new Ram 2500 diesel.
 
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