1986-z51

Car wont go into closed loop. What are the requirments for closed loop? my temp is good,new 02 sensor.can run engine up to 2500 rpm still no closed loop.I have seen cars fall out of closed loop at idle,But this 1 wont go in at all. Have my own scanner,am able to look at all readings.Imput please. oh ya 1986 coup

RRT vette

Last time I scanned my 86, closed loop started when my engine temp was between 140-150*. The O2 sensor is the main determining factor for closed loop operation. The O2 sensor voltage will jump around consistanly when closed loop operation has been reached. The exhaust temp needs to be around 600* before the O2 sensor will become active.

Another sensor or circuitry that will prevent closed loop is the Coolant temperature sensor. Check to make sure your not getting any codes via scanning. If both of these sensors are working properly and you don't have a exhaust leak upstream on the driverside, you might want to swap in a different ECM or prom (86-89).

CorvetteMike2024

This book is a must read if you want to understand how your engine works. 311 pages

1986-z51

I got it to go into closed loop by taking the boocsh 02 sensor out an put in a delco. Been chasing a lean code,so i changed the 02 sensor.Now i found the 02 reading low like in the 200 range,an the blm on 160.Order a set of fuel injectors from john today.