No afm on this engine, got a rough idle and bit of a lack of engine power unless i put my foot into it like 30-35%...

-STFT look normal, LTFT are slightly positive (+2 or +4 at the worst)
-It has a little bit of a tick only audible under the vehicle
-map and maf sensor data, as well as IAT are all normal
--no active or stored DTC'*
-on the first startup in the morning, I let it idle for 2-5 minutes to let it warm up a bit, in the summer around 2 minutes. I back out, I put it into drive. When i step on the accelerator pedal (only on the very first acceleration), there are 2-3 almost what feel like fuel cuts for half a second, the rest of the drive is normal. Never done it in 2nd or any other gear, just that first acceleration it cuts 2-3 times


-fuel injectors pulse really low at idle, only about 1.4-1.5ms at idle. I am used to seeing 2-3ms at idle


Any thoughts would be helpful. I am going to monitor stft during that "fuel cut" and see if there is any data there to see if its fuel related

How many miles on the vehicle?

What is the fuel pressure with key on engine stopped?

What is the fuel pressure with key on engine idling?

What is the fuel pressure during the [stumbling] event?

Does the engine speed go down during the [stumbling] event or up?

The RoT is IPW will be about the same as the displacement. A 6L engine should be about 6ms IPW.

ya so already super low but nothing to show for fuel trims, they are just typical -1 or -2 or +1 or +2 fluctuating and correcting at idle, but pulse width is as low as 1.4 at idle, cold its around 1.8 at idle

this doesnt have a fuel pressure sensor and the service valve is on bank 2, so I cant check while driving but I will try to get a passenger, getting a pressure tester in a few days and I will check. Vehicle has 113k miles on it. Engine speed does not dip at all during the event, it looks as if you were just normally accelerating, it just steadily rises and then shifts 1-2

ltft is now +2 on bank 2 only

Fuel Trims and IPW are not related like that. That thing seems like it wouldn't run that low. Why wouldn't the PCM add fuel?

They'll lean out if there is way too much fuel pressure. Not sure if that'* what is happening here, but it'* a possibility.

well what I mean is if there was something incorrect with fuel ipw being too low, fuel trims would be super negative since the ecm seems like its really subtracting a bunch of fuel. The other thing I have noticed (not sure if normal on this motor) is that just under normal acceleration it will sit at 35-40 degrees of timing, as in 35-40 btdc which seems high for just normal accel, cruising at speeds of 40mph it likes to sit at 50 degrees...

the weird thing is this doesnt have a fuel pressure regulator, I am pretty sure its a part of the fuel pump basket in the tank, but I am only seeing +2 which isnt a whole lot