Lcr99chevyls

Hey yall I could really use some help I just put a 2000 4.8 ls in my 99 Silverado same size motor that came out an For the life of me I can't get this thing running aright PLEASE TELL ME if yall got an suggestion from the info below

AdsoYo

iTrader: (1)

Another user in the Gen 3 External Engine section solved his P0300 code by doing a crank relearn procedure, worth a shot.

jetech

Did this engine run good before you installed it?

01WS6/tamu

iTrader: (37)

You are supposed to run crank cam relearn after the motor is replaced. It allows the pcm to relearn the crank and cam reluctor count error every engines different and you are even supposed to run it after cam swap.

If you do it and it still sets a po300 time for deeper diagnostics

Withers

Before installation, did you confirm if the engine ran good ?

01WS6/tamu

iTrader: (37)

Worth checking I've ran into this before on a few that have had outside work come in the shop. Verify each injector connector is on the correct cylinder.

LS1Formulation

iTrader: (13)

I have personally fixed my own '06 Silverado P0300 code by doing a crankshaft variation learn. As was suggested, try that first.

strutaeng

It's running very lean on Bank 1. So maybe it is an injector that wasn't plugged in correctly...

Assuming engine was a good runner...