2012 hemi tick fixed, but now won’t run

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FastEddy

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2012 Ram with 5.7 hemi 130K mi. Replaced cam and lifters, had heads redone, new gaskets, reset timing chain(was top dead center), checked all push rods after installing rocker rails. Tried to start engine...would not start then only would run at 2000 rpm or above then die. Checked intake no vacuum leaks, now wondering if the MDS system has anything to do with this? or is it programming? have done and redone and checked everything...just stumped. Anyone have any ideas?
 

DILLIGAF

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Did you use a cam degree wheel to check the cam install ?

Yes a custom tune is required if you delete MDS.
 

Tach_tech

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When it does run is it misfiring? It’s pretty common after a cam job for a push rod to jump out on the first start up. All it takes is 1 and it will run like garbage, or not at all.
 

Burla

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was old cam bad, or it just ticked?
 
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FastEddy

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When it does run is it misfiring? It’s pretty common after a cam job for a push rod to jump out on the first start up. All it takes is 1 and it will run like garbage, or not at all.
Thank you. You are correct, it is misfiring and won’t run at all. I checked them and they all were ok, but I will check again.
 

Tach_tech

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Thank you. You are correct, it is misfiring and won’t run at all. I checked them and they all were ok, but I will check again.

If you pull the valve covers again, it would be a good idea to have someone crank it over while you watch the valve train and make sure they’re all opening the same amount.
 
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FastEddy

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If you pull the valve covers again, it would be a good idea to have someone crank it over while you watch the valve train and make sure they’re all opening the same amount.
Thanks. I have turned it over and checked that the valves were opening and closing correctly, but this was before I tried to start it. I have the valve covers off now and will do that. If I see anything I will pull the rocker rails and pushrods back out and check them.
 
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FastEddy

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When it does run is it misfiring? It’s pretty common after a cam job for a push rod to jump out on the first start up. All it takes is 1 and it will run like garbage, or not at all.
Boom! You nailed it! Went back and looked closer and sure enough, one push rod was a little out of line. So I went ahead and pulled the rail, #7 cylinder intake pushrod slightly bent. Couldn’t hardly tell it was bent until I rolled it on the table....barely bent. Thank you...I would not have seen it without your input!
 
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FastEddy

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Still won’t run. Backfires. Timing chain? How can I set timing with the heads on?
 
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FastEddy

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This NOW has new push rods, cam, lifters, gaskets, timing checked twice(it is on compression stroke) and is correct, no vacuum leaks I can see, new exhaust manifold gasket and bolts. Still won’t run except at high rpm 2500 if I keep playing with throttle, will not idle.
Any ideas? I’m over it.
 

Tach_tech

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Do you have access to a scan tool to monitor misfires when it is running? Does it still have the MDS lifters or did you delete them?
 
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FastEddy

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Brand new MDS lifters...only ones I could find available. IF I can keep it running...or trying to run(only runs with me constantly playing with the throttle to keep it at 2500...if I stop it dies)I have am OBD scanner to check codes.
I did not delete the econo-mode. I would like to but I have not figured out how to do it on this year truck.
 

Tach_tech

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Are any codes set for any misfires? A proper scan tool would allow you to view misfires in real time.

Have you done a compression test?
 
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FastEddy

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Been thru this top end 3 X, timing dead on, replaced push rods, it is still not running right...multiple misfires, codeP0300. It only runs at 2500RPM or above, will not idle. Tow-haul on...starts better. Could MDS be the problem?
 
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