Different idle issue 2010 6.2L, driving me crazy

[Tm2525ai]

I already went through the PCM relearn procedure several times. It is always very bad idle until driving the 30 miles, then it gets as good as it gets, but still the same bad warm idle.

 

[B E N]

If this happened right after you were in the airbox to change the filter I would be looking at a vac leak. Pull the intake tube from the manifold to the filter box, make sure there are no cracks, nothing loose. Reinstall methodically making sure everything seats and the clamps all get tightened down.

 

[Tm2525ai]

Thanks, I have done that at least a dozen times now, and the dealer has, as well.
The initial problem was oil from K&N contaminating the MAF sensor, but I think the after market MAF I had on for a while screwed up the PCM and timing. The dealer reprogrammed the PCM, but didn't help, even after 100 miles of driving.

Have been debugging this for two months now, unfortunately.

 

[FordTechOne]

Did the dealer smoke test the intake system for leaks?

 

[Tm2525ai]

I think the Ford tuning shop did and I asked the dealer to check for vacuum leaks, but I will have to confirm they both did that.

 

[Tm2525ai]

Tuning shop did look at readings and doesn't think it's a vacuum leak. They suggest I change plugs, but not sure if that would affect rpm (50 lower) and timing (just little off).

 

[perry]

Are any of the hoses around your BEVIS, and brake booster hose where it connects to the manifold at a sharp bend. I had a sorta kinda similar issue. I think the hoses were rigid enough when cold, but after the engine ( compartment) warmed up, they flexed enough to collapse under vacuum causing rough idle and sometimes stalls. Long shot, but who knows. Similar issues with coils once they warm, I’ve found the little pills in the coil packs had corroded in my 2012. Not enough misfires to kick a code but they will show up with a scan tool per cylinder. Assuming your shop checked that, but again, who knows.

 

[Tm2525ai]

I think the idle is 'off' even when cold, it's just idling so high it's difficult to tell the pattern is wrong. It does sound different from before, but you can only really tell once it warms up. It's not even that rough (most of the time), just not the normal idle pattern. I will check hoses again, but I think the timing is off by the least amount possible. The tuning shop said plugs could have glazed when I was driving it with the MAF sensor contaminated with oil. I can inspect coils when I change plugs. Not really wanting to do that job, but will once the weather gets a bit warmer.

 

[MTF]

Where did you buy the replacement MAF sensor?
Have you carefully inspected the pins in the connection?

Also you have to careful cleaning the MAF sensor,
if you use the wrong cleaning spray or over do it with the MAF cleaner you can damage the silicone that seals it.
It' only takes one to two quick sprays from the MAF cleaner spray and don't touch or wipe it dry.

Also make sure the climate control is not set to defrost the windshield,
this makes the ac compressor turn on to dry the air flow and will increase the rpms.

And I too didn't like how high the rpm was on startup, my neighbors complain the first day I got the truck.
We don't have a resonator in the mid pipe like the 2011-2014 so it's louder. LOL
The truck would start at around 1,350 to sometimes 1,500 rpms.
On newer year Raptor they added a soft start feature that you can turn on and off.

Luckily when I put the Whipple on, I had the Turner adjusted the rpm startup and now it starts around 1,000 and quickly jumps down to 850 till it warms up, and settles to 600 rpm.

 

[Tm2525ai]

The replacement I got at my Ford Parts dept. new, and I used MAF cleaner on the old one, both now have the idle problem exactly the same. Defrost is not on.
The RPMs are 50 lower than always before at warm idle.