I just installed a 502 efi engine in place of a hp500 carb engine. Engine harness plugs right in to the existing wiring. No spark at this time. Fuel pumps running but now fire. Could there be a wiring issue with the existing wiring?

Thanks

see if you have power at the coil.if not look for a blown fuse where the steel box is that houses the ecm and all the releys..if all is ok then check the plugs and match the brass blades to see if the efi engine has more,,if it does then you will need a adaptor plug..im not telling you to use the boat like this but if you just want to fire the engine you can run a fused 20 amp wire directly to the coil,,this should energize everything..

Thanks for your input.

It has started and fine tuning from here.

Thanks