2001 GEN 3 Weird Idle

[bk2life]

This is a 1998 chevy truck swapped with a 5.3/4l60e.

This is what I am assuming a budget swap would be.
The ECM has some type of tuning down to it, and at first start this jumps to a loud 1200 RPM idle and then slowly comes back down to an 800 idle. I?m guessing this has straight pipes as it is loud.

I drove it around the block, and it?ll hold about 40 mph with no throttle.
It?s showing rich on the scanner and the more I look at the swap I hope someone didn?t pay a lot of money for the install. The wiring alone is enough to make you cry.
So, this morning performed the ?russ k? BRAF just to see where we are in the grand scheme of things, and about 8:30 (and 131 degrees ECT) into the scan the truck goes into a weird high then low idle ?surge?.

It is fine up to 8:30 and after nearly a full minute, it settles down and goes back to the approx. 800 RPM for the rest of the scan.
Does anyone have any idea what that idle surge was, or what might have caused it?

I have uploaded the ?stock? ECM and the ?modified? russ k version
And a ?stock? scan from driving it last night, and this mornings ?russ k? scan.
full pull.hpt
1st for BRAF.hpt
green c10 1st.hpl
BRAF 1ST.hpl

[bk2life]

20240514_093759.jpg20240514_093806.jpg

[edcmat-l1]

Cam? Injectors? Throttle body? C'mon man, you know the routine.....

First thing you need to do is rough in the VE/MAF. It's WAAAAY too fat right now to do any idle tuning.

[bk2life]

Cam? Injectors? Throttle body? C'mon man, you know the routine.....

First thing you need to do is rough in the VE/MAF. It's WAAAAY too fat right now to do any idle tuning.

lol... yea yea yea, just got this thing dropped off, just looking a things.
cam unknown, injectors unknown, Tbody stock

the rolling idle through me for a loop as it started out of knowhere and then dissapeared

[edcmat-l1]

Put everything you changed under "idle" back to stock. Set the idle speed you want. Up the BRAF a little bit. DON'T TOUCH THE IDLE PIDs!!!

Figure out exactly what injectors are in it. How you even start tuning unless you know EXACTLY what they are? Answer is, you can't.

Dial in the VE and MAF tables. THEN adjust your idle stuff. DON'T TOUCH THE PIDs!

[bk2life]

DON'T TOUCH THE PIDs!

it's like the floor is lava ...

32lb Denso #25326903 Flex Fuel Fuel Injectors

the fuel vacuum reference tube was split on both ends. Ive been smelling some raw fuel so i thin the diaphragm might be bad in there.

I'll do some mechanical work on this, before i come back.

[Alvin]

IAC is out 0.. meaning it cannot lower the idle anymore.

The IAC is either bad, or there is a airflow leak... vacuum leak, throttle body blade position, etc.

Easiest way to check IAC is use BIDI controls and set it to 128 and see if idle goes up.. 0 and the idle should go down.

[bk2life]

vacuum leak.

the vacuum hose to the fuel regulator is in 2 pieces.

This is why i hooked up the scanner so i can see what is going on before i did anything to it.

I know zero about this vehicle, and see someone has failed the MAF. So no clue if they were tuning VE and just stopped,
But, I'd like a stock file i could swap in and start fresh.

Not doing anything until i can verify no vacuum leaks.