I contacted the seller and said no way is he getting 40mpg. He won't even do the math with the numbers he provided .

1979 Datsun 280ZX 2+2

The ad reads it needs minor repair so I imagine something has broken in the engine to give 40 MPG.

The ad reads it needs minor repair so I imagine something has broken in the engine to give 40 MPG.

Nothing serious - just a little surface rust to clean off, slight alignment issue with the LF fender, a couple of mechanicals as stated, ...! As he said, nothing serious.

40 mpg and it does stunts,too? From the sellers description, it sounds like the only "stunt" it will do is "sit".

Dennis

Plugged fuel injectors actually will improve fuel milage on the highway. Two plugged injectors turn the 6 into a 4. City milage may suffer, and it won't get out of its own way... But many years ago I bought a 6 cylinder Volvo that ran really bad. I drive it that way for weeks, until I gave up and took it to a mechanic who discovered two plugged injectors. It ran a lot better after the fix, and actually did use nearly 50% more gas. (OK, maybe 25%-30%)

That is interesting Walter thanks for sharing that.

It might be a heretical idea but I have always wondered what would happen if a Z ran on only one carb with the other carb blocked off so the other three cylinders would be fed by the balance tube only. Would it run at all and if so would it affect gas mileage?

Last year after setting the carbs too rich and fouling the plugs, I set them up too lean. Ran crappy and I was afraid to get on it because it might damage the top end, but the mileage was great. Didn't calculate it but wouldn't be surprised if it was about 40 mpg.

Actually once you lean past best power A/F ratio, power will start to ebb while cylinder head temperatures rise. However, if you continue to lean the mixer, power will continue to fall but so will head temperatures as there is less fuel and some oxygen remains unused.

Charles Lindbergh made a major contribution to the WWII war effort by teaching severe leaning for ferry flights of fighters when crossing the Atlantic and the vast expanses of the Pacific.

Edited October 12, 201311 yr by djwarner

Shutting off one carb when you have three gave surprisingly decent power. Lost a bolt through the pushrod once. Knew it was down on power, but it was quite drivable.

Now if I had a magic way circulate between running on 1-2, then 2-3 then 3-1 then 3-2 I wonder if you could improve your highway mileage without hurting the engine much.

I have even wilder dreams....

Dare I ask? What wilder dreams?