I bought a 1990 300zx NA 5 speed with 104k miles a few weeks ago. I only average 12-13 mpg. What could be causing this? I don't drive the car very hard.

 

Its a 20 year old sports car. Dont expect good gas mileage.

 

I'm not expecting great gas mileage, but from what i've seen online, most people that have my year get at least 16 mpg.

 

maybe on the highway.

on the highway/parkway i get great mileage. stop and go / normal driving i get about 12.

 

Ok. I thought maybe it could be bad fuel injectors or bad spark plugs because sometimes when accelerating it seems like it loses power throughout the powerband.

 

there probably is something wrong then.

first thing to do, check the injectors. they should all ohm out between 11 and 14.

if theyre original, chances are theyre starting to fail.

 

how do I check them? and how much do you think it would cost to have them replaced?

 

Volt meter.

Same way you would check anything with it.

Pull of the connector. Set the meter to ohms, hold negative / positives on the tabs.

Probably looking at about a grand + between parts and labor. Probably pretty close to 1500.

Where are you from?

 

Shoot. Wasn't expecting it to be that much. I'm from Atlanta.