ZR-1 Net Registry Forums - View Single Post - Jumped the gun still having stumbling issues

-=Jeff=- · 05-22-2008

I have an ECM on the way tomorrow, will have it next week.. switching it no matter what.. did some Service manual reading..

the O2s are Biased to 450mV by the ECM, the O2 sensor then helps to adjust up or down (rich/Lean) there are 2 signal inputs to the ECM Left and Right O2. There are also 2 Ground pins on the ECM for left and right O2.. which are shorted together and then grounded to the engine. I ohmed between both Left right grounds at the ECM.. confirmed short... Ohmed from both to ground ( both chassis and engine) seems to be open.. I ran a new wire to creat the ground.. it is later here and I will nto get a chance to try again until saturday AM..

So that might explain the O2 problem, but not the changing BLM in Open loop..

05-22-2008	#19
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,167	Re: Jumped the gun still having stumbling issues I have an ECM on the way tomorrow, will have it next week.. switching it no matter what.. did some Service manual reading.. the O2s are Biased to 450mV by the ECM, the O2 sensor then helps to adjust up or down (rich/Lean) there are 2 signal inputs to the ECM Left and Right O2. There are also 2 Ground pins on the ECM for left and right O2.. which are shorted together and then grounded to the engine. I ohmed between both Left right grounds at the ECM.. confirmed short... Ohmed from both to ground ( both chassis and engine) seems to be open.. I ran a new wire to creat the ground.. it is later here and I will nto get a chance to try again until saturday AM.. So that might explain the O2 problem, but not the changing BLM in Open loop.. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Shelby Series 1 - Wilwood Brakes Custom Interior NCM Lifetime Member #978