mds delete w/ funny idle

[J pizzle]

I have recently replaced the cam and lifters on my dads truck. 2010 ram 1500 hemi. Normal problem of a lifter going down...but we went back with the lifters from a non-MDS hemi. it has a slight misfire feeling at idle. when you accelerate...the misfire goes away. Ive read that the cams are slightly different in the two engines, but it wasn't a lot. just enough to take up slack on the exhaust mds lifters. didn't know if anyone has figured out how to tune this out? still kind of new to this whole tuning thing.

[coanan]

Did you also use a NON MDS cam?

[J pizzle]

I went with a stock cam. Straight from the dealer for his Vin. I have since read forums about the lobes being different....was kind of Hoping that there was a way to tune it a little and make it idle right, without having to swap cams again.

[Homer]

By stock cam, do you mean MDS cam?
https://www.knowyourparts.com/techni...-hemi-anatomy/

According to MMX you must use a non-MDS cam when using non-MDS lifters.
http://www.modernmusclextreme.com/p-...ts-listed.aspx (scroll to the bottom)

[coanan]

I went with a stock cam. Straight from the dealer for his Vin. I have since read forums about the lobes being different....was kind of Hoping that there was a way to tune it a little and make it idle right, without having to swap cams again.

Looks like you'll be back in motor. Question is, cam or lifters.

[J pizzle]

Stock cam, meaning MDS cam.

[J pizzle]

Second vehicle we have done this to. The first guy says his does the same thing, but doesn't bother him. He's been driving it for a couple months now

[J pizzle]

for the record....bump idle up to 800 and its not noticable

[tyrell08]

Not attempting to steal this post by any means but I'm having very similar issues as the OP on a 2011 5.7 1500, #3 lifter ate the cam lobe and #5 lifter collapsed and stayed collapsed. Upgraded the lifters to hell cat non MDS lifters and installed a 2500 non MDS camshaft, went into the stock file and changed the MDS to disabled. Truck seems to have a misfire at idle, you can only breath on the throttle starting off or engine will bog down, and ECO light still comes on while driving under light throttle.

[GregRexAdams]

Bringing this back from the dead, just did a Jeep 5.7L with a TSP cam. It has the same idle. Any throttle or load and it goes away. Misfire counter is way up. Plugs look fine, it's on all cylinders. Anyone that ran into this ever figure out a fix?

[f.creek-ranch]

You cant mix the non mds with mds parts.
the mds engine has lower valve lifting on the mds cylinders.
if you want to kick off the mds use a 6.4 non mds cam. this is always a good idea, because it works perfectly in idle and you can use extra rpm in high range.

[PurpleRam]

Bringing this back from the dead, just did a Jeep 5.7L with a TSP cam. It has the same idle. Any throttle or load and it goes away. Misfire counter is way up. Plugs look fine, it's on all cylinders. Anyone that ran into this ever figure out a fix?

Since the cam is a tsp cam that is eliminates I being a MDS stick, not to sound like a jerk, but are you sure the push rods are seated?, what brand lifters?

9 out of 10 times this issue pops up, it’s mechanical

[skala308]

following with interest.