05-16-2010, 10:19 PM
Join Date: Nov 2009
Location: Palo Alto, CA
Total Cats: 0
Strange LC-1 problem
Hi all -
I've got a supercharged '93 with a MSPNP and an LC-1 wideband. Everything was working great for a while, but recently it's been running strangely and I plugged in TunerStudio to figure out why.
I was surprised to see that the AFR meter was pegged at full rich, no matter what driving I did. I didn't have time to deal with it at the time; I thought maybe I needed to upgrade TunerStudio since I just upgraded to Snow Leopard on my Mac. Today I upgraded everything, took the car for a spin, and discovered things were even weirder.
At first everything was working fine: AFR was reporting good values, as in the first attachment from below (all attachments are Megalog screenshots).
About 15 minutes into the drive, at the moment in the second log snapshot below, the AFR suddenly dropped to 10.286, and stayed within .2 of that value for the rest of the ride, no matter what happened to other inputs.
The rest of the drive looked like the third snapshot -- AFR dead rich, everything else looking fine.
I've checked connections on the LC-1 wires etc. Anyone got any other ideas?