Posted August 18, 200222 yr comment_13341 I have a 1981 280 ZX which has fuel injection. I know that this forum is used by mostly 240-280Z owners and that the ZX's are the black sheep of the Z family. However if anyone can look past the addition of the extra consenant (X) and comment on my question, it would be greatly appreciated.My car has an automatic transmission, so great gas mileage is not to be expected aka. 3500rpms @ 60mph. I was wondering if there is anything that I can replace or clean out in the fuel injection side of things that could help my fuel economy out. I was also thinking about trying to find a 5-speed to replace my 3-speed auto out with. I would also be interested in knowing if the 5-speed (driven like a grandma) might have increased any of your gas mileages.I understand that the Z-cars were not intended to deliver Honda Civic (blagh!) 38mpg fuel economy. However I would like to get atleast mid to high 20's if possible. Thank you for your input and time.Nerdofreak Link to comment https://www.classiczcars.com/forums/topic/2713-fuel-economy/ Share on other sites More sharing options...
August 19, 200222 yr comment_13399 You didn't say what mileage you are getting now, but I'm guessing it's less than 20? My 280 got low 20's with the stock motor. On a long trip, I noticed it dropped to 16-17, so I changed the air filter and my mileage was restored. With the vane type AFM, I haven't heard of anyone getting better than 24 or so with the factory setup unless they've leaned out the AFM so much the car has lost it's power.My '87 ECCS uses the O2 sensor when it's cruising to optimize the mixture, and on a 3 hour trip over the Rocky Mountains averaging over 80mph, I get 27mpg. HTH Link to comment https://www.classiczcars.com/forums/topic/2713-fuel-economy/#findComment-13399 Share on other sites More sharing options...
August 19, 200222 yr comment_13402 I am still working out the adjustments, so I am sure this will improve. But I get about 14 MPG .. I do however have a problem with the accellerator, it keeps slamming to the floor. I have tried to adjust it, I think it's a driver interface issue. Link to comment https://www.classiczcars.com/forums/topic/2713-fuel-economy/#findComment-13402 Share on other sites More sharing options...
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