[Unknown User]

During restoration of my 76 280Z a few years ago, the shopreplaced fuel injectors and converted the fuel supply bar to the more recent 280ZX model. Since then my car runs fine except the gas mileage has dropped to 17MPG including highway driving. Any ideas?

 

[ConorP]

I swing between 15-18 MPG on my '76 so that sounds about right to me. That's a completely stock 205K original motor with a 4 spd.

> During restoration of my 76 280Z a few years
> ago, the shopreplaced fuel injectors and
> converted the fuel supply bar to the more
> recent 280ZX model. Since then my car runs
> fine except the gas mileage has dropped to
> 17MPG including highway driving. Any ideas?

 

[Ron]

> During restoration of my 76 280Z a few years
> ago, the shopreplaced fuel injectors and
> converted the fuel supply bar to the more
> recent 280ZX model. Since then my car runs
> fine except the gas mileage has dropped to
> 17MPG including highway driving. Any ideas?

You should check to see what type of injectors were used to replace yours. If the shop installed the high-flow type your mpg should decrease but the increased performance is worth the sacrifice.

Also check the tuning on the car. Spark timing and fuel-air mixture (adjustable on some 280s) can be the difference.