Alright. I am not a ford guy. VWs are what I'm comfortable with. I'll start by saying I have searched the forums extensively and followed up on some of the info I've gotten, but I'm still stuck.

I just locked out the cam phasers on a 2005 f150 with a 5.4. It now idles pretty rough. If I blip the throttle the revs will rise and then drop again, and it barely catches in time to prevent a stall. If I continue to tease it this way I can usually get it to stall. I'm getting no CELs or anything, but I intermittently will get a P035x code (it seemed to rove. I've gotten cylinder 1, 4, 6, but not consistently.). I have chased those around by swapping coils, checking/cleaning the connectors, etc. I am kind of thinking that these codes are a symptom of my idle issues, and not the actual problem. What could I have done wrong? Could it be a vac issue? I had basically the entire ECU harness and all the vac lines disconnected to do the job, but as far as I can tell everything has been reconnected to the correct locations. If anyone can help me sort this I'll be incredibly grateful. Thanks in advance!

Oh, and I did have an SCT tune done to remove the phasers in the ECU. I installed it and still have the issue, so for now I am on the stock tune just to eliminate any variables.

Edit: could my tune be the issue? Is this how you would expect the engine to behave with locked out phasers and no corresponding ECU tune?

 

Alright. I am confident I've ruled out vac leaks. I've cleaned the MAF and the TB. Still no improvement. Next I'll clean all the coil boots and plugs, but I think I'm grasping at straws with that one.

No suggestions? I'm stumped.