[Eric_FJ40]

My FJ40 has typically gone through a tank of gas much faster than the other Cruisers around me. I'm pretty sure it's running rich.

The carb has been rebuilt and adjusted and works flawlessly - no complaints there.

I suspect the jets are too big. I have not been able to remove them - as one is buggered up from a couple attempts. I figured I'd leave it alone until it was time to remove and re-jet (so I don't know what's in there now).

Is there a guide for what jets to use at certain elevations? I am only about 100 feet above sea-level. I'd like an idea of where to start. FAQ and searching did not help...

[Pin_Head]

I am not aware of any guide or table for jets and I am surprised by the different sizes I have found in different year carbs. It you want to know if it is running rich, take it in to a shop that has a tail pipe gas analyzer and find how much CO it makes under different conditions.

There are other reasons a carb may run rich other than the main jets. Unless someone has changed jets, it is unlikely to have left the factory set too rich. One major reason for running rich is that the engine has been improperly "desmoged" and the power valve vacuum line has been disconnected, leaving it open at all times. Another reason is that the air vents in the emulsion tubes and fuel delivery passages get plugged by a careless rebuild.

[Eric_FJ40]

Thanks for the response, Pin Head.

This is a 12/78 Cal Spec engine with all the smog intact and (to the best of my knowledge) functioning. I see now that there could be many factors involved in this.

I should get the exhaust analyzed so I know for sure - then go from there.

[65swb45]

A 78 Cal-spec'd carb actually runs one of the smallest jets Toyota used in the 2F, a 1.24 IIRC [as opposed to a 1.47 for an FJ60 2F carb], so I'd be more inclined to look at the power piston/power valve scenario Pinhead mentioned IF it is truly a carb problem.

Fuel economy is affected by many other things as well. Tire size, tire pressure and wheel alignment for starters.

Do a thread search on MPG and see if you're in the general ballpark. These motors don't 'sip' gas.

Best

Mark A.

[Eric_FJ40]

Thank you, Mark.

I may be able to check the jet size at some point if I can get them out...