408 LQ4 problems

[farmtruc]

Since the hesitation went away when pulling disabling the maf, might be a dirty maf or the PCM thinks there is a lean condition or there is one.
A map sensor doesn't respond the same way to a vac leak.

What are the ltrims showing when the ma is plugged in?

[mr2cam]

Since the hesitation went away when pulling disabling the maf, might be a dirty maf or the PCM thinks there is a lean condition or there is one.
A map sensor doesn't respond the same way to a vac leak.

What are the ltrims showing when the ma is plugged in?

You mean the fuel trims? This morning before we did any revisions with the base tune it was showing good, I think one bank was 0 and the other was -3 on the Verus. Also when I sent Vince the first data log he thought the fuel trims looked good, but the truck does act like it is running lean.

[mr2cam]

I should also say that once the truck is driving it is smooth as silk, drives very nice..

[farmtruc]

There are so many things that could be going on.
Good ltrims indicate there is no leak and the o2's are working.
The fact that the engine runs with the maf disconnected means the map is working, actually since the trucks starts at all means the map is working.
Good ltrims also means the fuel pressure is ok, as long as the ltrims are around 0 during idle and normal driving (loaded).
o2's good, map good, no leaks good, fuel pressure good, only thing is the maf, be sure you swap it out just to make sure it's not that. I've seen weird things happen due to a maf.

[mr2cam]

Well we put a brand new MAF in the truck and still does the exact same thing, kinda stuck here :\.

[farmtruc]

Well we put a brand new MAF in the truck and still does the exact same thing, kinda stuck here :\.

sounds lean, have him richen it up quite a bit, and lower PE threshold to 30

[mr2cam]

sounds lean, have him richen it up quite a bit, and lower PE threshold to 30

K, he sent me another tune and it made things even worse, truck barley ran and died at almost every stopsign, I datalogged it for him and he will hopefully have another one back to me soon.

[farmtruc]

not sure what to tell you on the tuning side, i know i take offense when others recommend without knowing the full details, so i don't wanna do that.

just be sure all the mechanical stuff is in order, or the tuner will have a nightmare trying to tune around it.

i'll keep racking my brain and try to suggest some stuff.

[mr2cam]

not sure what to tell you on the tuning side, i know i take offense when others recommend without knowing the full details, so i don't wanna do that.

just be sure all the mechanical stuff is in order, or the tuner will have a nightmare trying to tune around it.

i'll keep racking my brain and try to suggest some stuff.

We have checked just about everything we can, here is what the tuner said last.

"It is not running lean. Fuel trims look good. It’s just that the PCM isn’t adapting for the idle properly"

[mr2cam]

I'm wondering if it's having a problem with the 102mm throttle body and huge intake..