Hello all I have a 2001 Camaro LS1 in my 1951 Cadillac that’s been swaped and I’m having issues with engine vibrations. I replaced the mounts because they were custom made. Had the ecu tuned and gone through. The harmonic balancer was really wobbly so I replaced it seems to fix it a bit. Unfortunately I still have a pretty bad vibration and a slight knock at idle but gets quieter as it warms up. So I pulled spark plug wires off the coils as it was running to check if the engine tone/ram change. So I found that cylinders 2,8,3,5 all didn’t change how the engine ran when I disconnected the plug wire from the coil while running. Does this mean it’s bad coils?injectors,plug wires? Plugs? Plz help any input is appreciated

 

Could be any of that stuff, improper wiring, bad grounds in the harness etc etc, have to keep digging til you find what changes it

 

As said above check the grounds. Also check to confirm you have the coil and injectors plugged in correctly as in the firing order. Also check for 58 psi at the fuel rail.

 

There's a tune/diagnostics forum for this type of help.

 

Where you not getting any misfire codes?

 

The LS firing order is 1-8-7-2-6-5-4-3. That would indicate every other cylinder is not firing. Not sure if that is helpful or not. Maybe add Crank Sensor to the usual suspects.