Hey guys,

Was wondering if anyone has had this issue, I have a jdm Evo 7 with ayc/acd and recently ive been trying to figure out the cause of a large voltage oscillation in WOT which also causes my AFR to oscillate. Found out its the AYC pump. The voltage oscillates every time the AYC pump activates/pumps.
I pulled the relay for the ayc which is on the firewall on right side of engine bay which in turn shuts off my AYC pump and my voltage is completely linear now and so is my AFR. I'm sure the AYC pump still works and builds pressure, there's just something about that system causing a large voltage draw/oscillation. I noticed the connectors/pigtails for the AYC pump are pretty crusty looking so im gonna start off with cleaning everything and using dialectic grease. If anyone had any ideas as of why my pump is doing this that would be greatly appreciated!

Thanks

 

check all your grounding points.. AYC pump motor draws a lot of current