I bought this truck with 218K with a miss fire to flip it. While looking it over I touched the cylinders exhaust port that had the miss fire and was cool compared to the rest. Took it home figured it would be a lifter. Pulled the cover and what do you know. Failed lifter. Pulled heads and had them gone through at local shop and shaved. R/R all lifters keeping AFM/DOD trying to just get it done quick to flip. Put it all back together and is now missing in #4. Spent 10 hrs chasing what it could be doing everything. Compression tests, spark testing, injectors. Nothing. Pulled the cover and turned the motor over to find that the intake valve train cycles at random and when it does, does it well. Sooo. Why random? What would cause this issue? Bad “valley cover”(not sure the actual term for DOD). The motor oil was black as hell. And had a lot of sludge internally. Thinking maybe something is clogged or something. I don’t know.
tried posting a video but a 10 sec video is to big I guess. Thanks for the input to any.

 

If the valve train doesn't cycle normally you may have a worn cam lobe.

Most folks will delete the AFM/DOD stuff but that requires a new cam and lifters (just the regular lifters x16).

 

If it was a cam then it wouldn’t be random though? Right?
I should have done the delete looking back. But wanted it just simpler just to get it sold quicker with less work and money.

 

Yes, I agree with you on the randomness...

I'm not certain what would cause that?

You replaced all the lifters, right? You bought the correct lifters for the AFM/DOD system? Like there's 8 special lifters and 8 regular lifters.

 

Correct. I replaced all 16. And the 8 DOD got put in in the correct direction in the lifter tray.

 

I seem to recall reading something about replacing the VLOM in the event of a failure.

 

So the vlom is what I referred to as the valley tray? That’s what I was considering bad I just know nothing about it. I have never replaced dod just delete it so I am learning new things.

 

I have never replaced DOD either only delete.

 

Well replaced the vlom. Still same issue. Guess the head is coming back off. Only thing I think is the next step.

 

I forgot to put in the info. But finally got some time to dig into this. Pulled the passenger side head off. Pulled the lifter tray and found SOME how I got the lifter in backwards. Dont know how but I managed. Through it back together and is driving and running great. Pretty dumb move.