Help with rough idle after AFM delete and new camshaft.

[[email protected]]

I did an afm delete on my 5.3 and replaced the camshaft with a 4.8l one. The truck runs well except it has a rough idle. No codes, no misfires but feels like a misfire. Changed the plugs, changed the wires, cleaned the MAF, cleaned the throttle body, checked the spark from each coil, did a smoke test for vacuum leaks. Still the same stumble at idle only.

Here are the specs in the camshafts. Where they are slightly different and if the timing change is the cause for my rough idle, could this be tuned out? Any help is appreciated. Thanks.

New Cam: 12689035
Duration: Intake: 190, Exhaust: 191
Lift: Intake: 0.466?, Exhaust: 0.457?
LSA: 114

LC9 (old) Cam 12588614:
Duration: Intake: 196, Exhaust: 201
Lift: Intake: 0.481", Exhaust: 0.481"
LSA: 116+2

-Jamie

[5FDP]

Post the tune.

Also if you didn't replace the lifters, you did it wrong. You can't run AFM lifters on a non AFM camshaft.

[[email protected]]

I replaced the lifters. I?m interested in wheather my rough idle can be tuned out based on the differences in the cam shafts.

[5FDP]

I asked for the tune to make sure you turned off all the correct things for the AFM delete.

Past that you can raise the idle from 525 to like 650 and they always smooth out.

[danmw2003]

If you were just asking the question of "can it be tuned out" but you havent purchased any tuning equipment, then yes. You need to tune it and turn off codes and disable the DoD in the calibration. A compression and leakdown test will tell you if you have any mechanical issues prior to spending money, if you havent done so yet. Also, when you ask questions here on this forum, its a MUST that you provide a log and the current calibration for others to review. Otherwise, we really cant help you much.

[edcmat-l1]

This another guessing game? Should I break out the crystal ball????

[Alvin]

If you disable DOD and do not disable the codes it will act like its missing at an idle.

[2xLS1]

If you disable DOD and do not disable the codes it will act like its missing at an idle.

No it won't.

[Alvin]

No it won't.

Maybe let me rephrase. IF you swap to non dod hardware but do not disable the codes in the tune.. it will act like its missing at an idle.

[danmw2003]

Oooh! I wanna see that crystal ball!!!

[2xLS1]

Maybe let me rephrase. IF you swap to non dod hardware but do not disable the codes in the tune.. it will act like its missing at an idle.

If the main DOD switch is set to disable it will not run the test for the DTCs. I'm not saying it is good practice to leave them enabled but I have tested it on multiple MYs and OSs and if you just set the switch to disable it will not set the codes even if they are left enabled.

[danmw2003]

If the main DOD switch is set to disable it will not run the test for the DTCs. I'm not saying it is good practice to leave them enabled but I have tested it on multiple MYs and OSs and if you just set the switch to disable it will not set the codes even if they are left enabled.

I agree, simply because I have done this myslef. Not knowing any better. In fact, I'm pretty sure someone here on this forum corrected me on this at one time, when I asked for someone to review my tune. Pretty sure someone said it was half assed lol. It did not throw any codes, or exhibit any issues when the codes werent disabled, I just switched off the main DoD. This was on an E38 though, on my personal vehicle. I cant speak to other PCM's or Operating Systems.