Lml stuck in high idle?

[Wyatt.bilodeau]

Hi all, I just swapped an lml engine into this truck and it seems as if it’s stuck in high idle when it starts? Im guessing it’s around 1200 rpm as the rpm gauge doesn’t work and if you hit the break it will idle down to what sounds like just above regular idle until you let off the break. I’m getting codes for the maf sensor and the accelerator petal position sensor aswell. Any help would be greatly appreciated!!

P2138-00
P2128-00
P0098-00

Also if I can figure out how to upload a video I will do so of it starting up

 

[2004LB7]

You need to fix your throttle codes first

You can upload the video to YouTube and copy the link here

 

[Wyatt.bilodeau]

Hi all, I just swapped an lml engine into this truck and it seems as if it’s stuck in high idle when it starts? Im guessing it’s around 1200 rpm as the rpm gauge doesn’t work and if you hit the break it will idle down to what sounds like just above regular idle until you let off the break. I’m getting codes for the maf sensor and the accelerator petal position sensor aswell. Any help would be greatly appreciated!!

P2138-00
P2128-00
P0098-00

Also if I can figure out how to upload a video I will do so of it starting up

Below I have attached one video with the truck running with the other engine (broken crank) and one video of the truck running now.

Source: https://youtube.com/shorts/u44k8SP4umA?si=AyW5Mw6clZl7d4VJ

Source: https://youtube.com/shorts/2Bo8WnWJey0?si=JK3aE4DyOvigV0An


Also I have learned the truck is idling at 1000rpms and 800 ish when the brake is depressed. My cts3 can read the rpms

 

[Ron Nielson]

Check your DTCs here: https://www.dtcdecode.com/Chevrolet/P2128

 

[Wyatt.bilodeau]

Check your DTCs here: https://www.dtcdecode.com/Chevrolet/P2128

The petal codes ended up disappearing, now it’s just the air intake temp code. I got the truck to run fine lastnight then this morning it went into limp mode again. Didn’t do anything to fix it, just has a mind of its own

 

[darkness]

I’m not much help here but it’s either wiring or the maf. It’s going into elevated idle cause it thinks it’s cold. My lly will do the same thing when I have the maf unplugged.

 

[Chevy1925]

Better check them bail connectors

 

[Wyatt.bilodeau]

Better check them bail connectors

How would I go about checking something like that?

 

[2004LB7]

How would I go about checking something like that?

Open the connectors and look closely at the pins. Make sure none are bent or pushed back. Pull any "short" pins to relock then in the correct position.

 

[Wyatt.bilodeau]

Open the connectors and look closely at the pins. Make sure none are bent or pushed back. Pull any "short" pins to relock then in the correct position.

All good with the pins and everything after inspecting. Thank you!

 

[MarkBroviak]

ECT sensor or the connector for it can cause this to happen also with the high idle cause the ecm thinks it is freezing temps when it isn't.