MSefi.com read only forum (Jan.15,2018)

I've continued to have problems with my install, with the mixture periodically leaning way way out. Just recently I installed a AC filter on the 12v in for the MSIIv3/relay board set up and it started running great. Then when I went to update the tune file it started running horribly, leaning out on a much shorter, more violent cycle, so I loaded my old tune file and it still had the same problem. Eventually the symptom subsides so I try it again and again it pops up. This time I burst logged it and while the 12v IN varies by only a tenth or two in voltage and has no AC signal, the TPSdot has a lot of noise, but the TPS itself is steady. Any ideas?

Rather than try and filter a dirty PS, it would be better to provide a clean one. And or suppress what's causing the excess noise at source.

However, how is the TPS grounded?

The TPS is grounded at the relay board