Ok so I put a 94 iron head lt1 in my 89 I used a factory z28 harness. I cant get it to idle but if you give it some throttle it will rev up but will not go full throttle. It reads error 18 injector intermittent fault witch I have off in the pcm it was set from the factory. Why will it send a codes that is off ? I’m using a 94 cop car pcm with a 95 z28 harness. I need to get the thing to idle anyone have some suggestions

The fuel is 45psi
it gets a lot of knock when it starts
If you need to know anything about the car ask

I think the pam is bad I sat in a cut in haft car for about a year and was in water and dust butt it seams to read all the sensors well. I did flash it with a 95 5.7 t/a I got off my brothers car but it changed nothing

Thanks Tyler