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Started about a month ago with a cylinder 7 misfire. Replaced my lifters after inspecting both lifters (lifters had very light wear, no problems rotating) and camshaft (found no wear on camshaft). The lifters I put in were all non-MDS. The car has a 93 octane diablo tune on it. I've also got entirely new spark plugs. Cylinder 4 now has a misfire code in addition to a random misfire code I got on initial startup. I have a log file from my diablo tuner but cannot attach it to this post. Could someone inform me how to attach the file and also, more importantly, help me figure out whats causing my misfire?
 

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Started about a month ago with a cylinder 7 misfire. Replaced my lifters after inspecting both lifters (lifters had very light wear, no problems rotating) and camshaft (found no wear on camshaft). The lifters I put in were all non-MDS. The car has a 93 octane diablo tune on it. I've also got entirely new spark plugs. Cylinder 4 now has a misfire code in addition to a random misfire code I got on initial startup. I have a log file from my diablo tuner but cannot attach it to this post. Could someone inform me how to attach the file and also, more importantly, help me figure out whats causing my misfire?
You put non mds lifters on a MDS camshaft. Bad JuJu. It may "worl" but you will get misfire codes. Only real fix is to either put mds lifters in, or put a non MDS cam in. Stock wise a Challenger 6 spd cam would work.
 

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If I need to change my cam at this point, I'll upgrade to a 392 cam, springs, and pushrods. I've seen multiple places where people saying non mds lifters work fine with stock mds cam :unsure:, even a few of my chrysler master tech friends. So barring damage to the cam I want to think its not the cam. I've also unplugged mds solenoids and turned mds off in diablo.
 

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CE9311 has been there and done that learning the hard way.
The MDS cams have a different ramp profile to accommodate the MDS lifters when in MDS mode.

If not a wrong cam and lifters issue it could be valve seals popping off if you used Felpro seals. Does it miss and run rough when the code is tossed? Does she puff smoke on startups? If so pull plugs on that cylinder and have a look.

Good Luck
 

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If I need to change my cam at this point, I'll upgrade to a 392 cam, springs, and pushrods. I've seen multiple places where people saying non mds lifters work fine with stock mds cam :unsure:, even a few of my chrysler master tech friends. So barring damage to the cam I want to think its not the cam. I've also unplugged mds solenoids and turned mds off in diablo.
I'll put it bluntly (don't take it personal), when people start mentioning having friends as Chrysler Master Techs when they refute advice given on the subject. If they were as insightful and knew everything as implied with the word "master" in their titles then people wouldn't be here asking us general un-educated folks for help.

Just so you understand, I listened to several "master techs" and people and did the same thing. I got a P0300 misfires, a funky exhaust note, valve train noise, and a car that just didn't run right. I was told elevating idle would also solve it. It did not. This situation cost me alot of money and work so I am little jaded with it.

After researching difference in the cams, I learned that the MDS cam has different ramp and lobe profiles due to the check valve design of the mds lifter, as well as the advanced timing of the exhaust lobes on four of the cylinders. Physically the cam is different. Just like the lifters. Where as it may "work" it is not done right. Yeah you can put substitute broccoli in a receipe where its calling for bacon. And it still be edible. Does not mean it's going to be right tho.

I swapped out to a Challenger 6 sp cam, P/N #53022064BD ($80 bucks on rockauto) and my P0300, exhaust note, excessive valve train noise all went away and the engine felt more, how you would say "right".


Now, am I 100% sure this is the issue no. I can never be. However from personal experience I give you the advice based on what happen to me. I always suggest you research it yourself, read countless threads, and find out what you need.



Also note, 91 octane tune will serve you better in long run running 93 octane. Several posts and dynos on Challenger forums showed more power continuously from not having spark knock. Also, difference in power is less than 5hp generally, specially on canned tune. A lot of the canned Tunes work in giving you power is the throttle booster in making you feel faster. Same as a pedal commander.
 

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So are you going with a non-MDS 392 cam & lifters, or MDS cam and lifters? Just curious, always interested in builds. Keep us posted.

FYI I'm running a stock block 5.7L, MDS cam & lifters with 7psi but have MDS function tuned off. The lifters are new and have never been in MDS mode. I shift @6k RPM no problems. Silent valve train.

New lifters, springs, push rods, and seals @135,360 miles.

Keep us posted, pictures?
 

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So are you going with a non-MDS 392 cam & lifters, or MDS cam and lifters? Just curious, always interested in builds. Keep us posted.

FYI I'm running a stock block 5.7L, MDS cam & lifters with 7psi but have MDS function tuned off. The lifters are new and have never been in MDS mode. I shift @6k RPM no problems. Silent valve train.

New lifters, springs, push rods, and seals @135,360 miles.

Keep us posted, pictures?
I'm going with a 392 non MDS cam with performance springs and hardened pushrods. I'm also putting on a 392 intake manifold and SRV controller that will kick in at 4800rpm then ill get the whole thing remote tuned.
 
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