I notice a raw fuel smell in the exhaust on my 280Z, and after checking all kinds of things, it ended up being a broken conductor in a spark plug wire!

I replaced that wire and now there's no fuel smell, the engine idles more smoothly, the fuel gauge moves slower, and I'll figure out the MPG later.

thxZ

how can I tell how much mpg im getting in my 280z?

Use the standard method for figuring MPG:

1. fill the tank, and mark down the starting odometer reading

2. drive at least 1/2 tank

3. fill the tank again, and mark down the ending odometer reading

calculate the difference in miles, and divide by the gas to fill the tank

read this: wikiHow page

Or use the tripmeter. Zero it out when you fill up and then at the next fill up, divide the tripmeter reading by the number of gallons.

FYI

After 2 tanks of gas (91 octane), my stock L24 with new ZTherapy SU's is getting an average of 21 MPG. And since I just finally go it on the road after a 7 month restore, my foot is probably a little heavy right now. :devious:

Well, I filled up for the 2nd time (I use 91 and 92 Octane) and put another 208 miles on my 240z, got 20.6 mpg. Still ran about 50/50 Highway versus City. I pushed it a little more, and hit 100+mph on two occasions and did 5-6 quick starts and accelerations having some fun. Anyway it wasn't too bad. Soon I'll go on a 190 mile road trip with ~20miles city, the rest highway, anxious to see how it goes.

i fill up with 87 octane and get 24 to 26 mpg. i have a 73 with stock L24 and newly rebuilt su's.

nahurry , that's great! What's your timing set at if you run 87 octane? Can you also advise what percent on average is City vs Highway miles when you achieve 24-26 mpg?

Many thanks ,

my timing is 7 degrees B.T.D.C. and i drive mostly highway.

Many thanks 'nahurry". With my Mallory Unilite Breakerless Distributor my timing at idle is 15-16 degrees BTDC and at 3000 rpm is at ~38 BTDC. I get some pinging with 87 octane when I tried it. Anyway hope I get as good mileage as you when I take my little road trip in a week.

$1.42.8 a litre this week - soon to go up again. Time for postal workers to deal with oil executives - this is grossly offensive.

I run 89 octane on my rebuilt P-79/F-54 combo with stock (for now) '72 SU carbs. On the highway with my early 5-speed and 3.9:1 rear end combo I average just a little over 25mpg at around 3700 RPM. I got horrible mileage once when one of my fuel lines on the bottom of the carb developed a pinhole and leaked all over for hundreds of miles. Had to hitchhike on the res to the nearest gas station.