Got it running!

[Factory Guy]

Just finishing up my first LS swap into my Squarebody LQ4 and a 4L80e.

I haven't take her on maiden voyage as I cannot keep her idling?

I am using a MAF and a MAP and both O2 sensors, (the fronts I believe), its DBW, stock coil packs. 2003 tahoe ECU had vats removed and was fleshed by BRENDON at LT1swap.com

His side kick Adam did my LS wiring harness.

The dual fuel tanks set up wiring was done by Jabin Wood. (however I only have one tank hooked up at this time).

The truck starts good however it will rev up to about 2000 rpm's, if I don't keep my foot feathering the throttle it will slowly end up dying.

All of the Drive by wire stuff is stock GM, from a 2003 Tahoe, I got the ECU for the truck and the tach module, the wiring loom from the tach module to the accel pump and I also got the Accelerator pedal. No I do not have a fuel psi gauge in line on the fuel rails.

Picture below is my install.

Suggestions what to look for to keep her idling?

[Joyridin]

Is the MAF sensor located in about the middle of that straight stretch of intake tubing?

[Justin71105]

If you have the odb setup, get a reader and pull codes as well. Mine had 2 issies when I first got it running.

Cant remember code #s but one issues was dbw module, wouldnt rev consistently. Replaced module with one from junkyard and been fine since. So cheap I got two of them and tested both so I have a spare as well now.

Second was cam position sensor, really the wiring on connector, but this just made it spin over several times before actually starting. Had to crinp pin onto wire fully for that one.

Reader picked up codes for both then had to drill it down from there.

[Factory Guy]

MAF SENSOR is located at the air box end of all the tubes, as i understand it, it needs at least 6-12” of tubing in order to “flow” correctly.

[Factory Guy]

Whats really strange is i started this same engine/set up and all the same components outside the truck and let it run for a minute or so, 6 months ago. It idled fine then.

[jessemthompson]

Having your MAF that close to the 90* bend is going to cause issues. The airflow is disrupted in the bend and is going to throw off the reading.

[Joyridin]

That may not work. I had a similar set-up and messed with it for weeks before I realized what I had done. It needs to be about in the middle of that long tube or even closer to the throttle body. The air is coming around that 90 degree bend and missing the MAF sensor.

Try unplugging the MAF sensor. It should run and see if that doesn't fix the problem.

[Factory Guy]

Originally Posted by Joyridin

That may not work. I had a similar set-up and messed with it for weeks before I realized what I had done. It needs to be about in the middle of that long tube or even closer to the throttle body. The air is coming around that 90 degree bend and missing the MAF sensor.

Try unplugging the MAF sensor. It should run and see if that doesn't fix the problem.

Thanks guys I will give it a try!

[Joyridin]

Originally Posted by Factory Guy

Thanks guys I will give it a try!

Maybe I need to clarify my comment Unplugging it will put it in speed density mode and it should run assuming the tune is done correctly. I would not leave it unplugged, but that should give you an indication if that is the problem.