fuel injector impedance

No info about your car's model year, EFI or carb, no mods listed. Makes it hard to troubleshoot when we don't know what you have.

That's why it is a good idea to use the sig under the user control panel (User CP) option. It allows you to post your car year & mods, which help greatly when troubleshooting things. No, it is not there for us to snoop and see any "Secrets" you have hidden away under the hood. Be a good stangnetter and update you sig for future reference & don't keep us guessing.

What engine changes are you running? The stock 19 Lb injectors are good to 275 HP with some margin for error.

Changing the injectors from anything else other than the stock 19 Lbs will require an aftermaret MAF calibrated to the injectors or a custom burned dyno tune chip to match the injectors.

Google the numbers on the injector... that usually comes back with all the details...