5.3 LC9 AFM Delete

[CRTD]

Anybody have trouble with one of these? I did the master disable on the AFM, Cylinder Deactivation or DOD whichever you prefer to call it.
Customer has had another shop replace cam, lifters, guides, lifter cover, timing set, push rods and valve springs. All stuff they got from Summit.

Comp Cam 54-414-11
XR269HR-14
525/532
216/220 @ .050
LSA 114
ICL 112

Here's my question. Before I get started the thing runs strange. Seems to be racking up misfires on Bank 1 cylinders 1,3 and 5 mostly. But gets some on Bank 2 also. Came in with the calculated alcohol content at 55%. Reset that and seemed to help some. But not enough. You can feel it run rough and the LTFT is going on and off. The LTFT goes as low as -10 to -12 at times but doesn't stay consistant. Will set P0300 if you let it sit and idle long enough. My gut says there is something wrong. Before I spend time trying to compensate for what seems to be a pretty small camshaft to me.

Thanks

[5FDP]

Could be off a tooth.

Otherwise tuning for the cam is still needed but having random misfire would make you chase your tail. Have you inspected the spark plugs or swapped wires around to see if the misfire follows?

[CRTD]

I plan to tomorrow. Idle MAP is about 47 kpa. I have noticed that when it is in open loop it runs better. As soon as it goes closed loop it runs terrible. It will go on and off like this about every minute or two. Seems like cylinders 2,4 and 8 are misfiring as well. But not as much as the Bank 1 cylinders.

[Rigo_eff1fitty]

Check your main coil power source for humidity happened to me once

[CRTD]

So this thing has something going on that causes it to run poor in closed loop at an idle. MAF correction does not seem to help. Driving down the road it's OK. While idling hot in closed loop it runs poor. Misfires on almost every cylinder. After about a minute close loop goes off, the O2's go high, and it runs better. This cycle repeats over and over.

Start viewing the log at about 8 minutes in for the idle behavior.

Hopefully I missed something easy.

Thanks

[CRTD]

We double checked the cam installation and found they had used a Cloyes Hex-A-Just timing set. It wasn't installed correctly. We put in the GM stuff and that is all better now. Satisfied with that stuff now. I have noticed we now have a decent idle quality with the MAF unplugged. With the MAF/IAT in play the idle is rough misfiring on all cylinders and neg fuel trims. Is it possible we have some table that needs addressed before we go further? or is it more likely we have a defective MAF?

[CRTD]

Is there an easy way to keep it out of closed loop at an idle?

[CRTD]

I figured out what I was doing wrong. Runs better now thanks.

[07avalanche]

What was the issue with the afm misfiring?