So I bought a ca16de and swapped over all of my ca18det parts that were known good. Intake manifold eith butterflies amd 370cc injectors. Ca18det cas, maf, tps, cts, etc the only thing ca16 is the longblock. It idles rough and sounds like a Subaru. I checked the plugs that I just put in brand new ngks and they are black but not saturated. I'm thinking the rings aren't seated since this new engine sat for a while in the garage for about 4 years. But it had 30k on it total when it ran. I poured oil down the cylinders and let them soak overnight. And I will be doing a leakdown and compression test. But what would cause this to run bad? Faulty maf? Bad coolant temp sensor? Low compression? Or rich mixture from ca18 ecu on ca16 engine?