What other than the carburetor could cause poor gas milage on a 1985 ford ranger 2.8l?

Answer 1

There are many factors to consider when trying to acquire a better MPG in any vehicle. The best advice I can give you is to make sure your vehicle is in the best working condition it can be.

Check to make sure your carb is working right by checking the spark plugs. Run the vehicle normally for a while (say, 1000 miles on new plugs). Then, with the engine warm, remove several (or all) of your plugs a check them. Dry, sooty black deposits indicate a 'rich' condition (using, but not burning, too much fuel). A nice light caramel or near white color is best and indicates a correct air fuel mixture.

Run a cylinder compression check and make sure all cylinders are within 5% of each other, and are generally around 140 lbs. A low cylinder, or cylinders, would indicate an internal problem and the engine should be serviced to determine the cause.

Oily plugs indicate serious damage or wear and you should have your engine serviced to determine the cause.

Wet plugs would indicate that cylinder is not getting an ignition spark.

Remember, one bad cylinder accounts for a 16% performance and mileage decline for a V6.

Ignition timing, spark plug gap (around .045 for your vehicle), ignition coil, tire pressure, transmission slipping, missing, disconnected or incorrectly routed vacuum lines, EGR valve, catalytic converter, tire alignment, air cleaner, regular oil changes, all contribute to your cars efficiency and need to be repaired or maintained. There usually is no quick fix or single problem when trying to determine why vehicle MPG has dropped.

If your engine is sound and everything above is in good working order, then upgrading existing systems may provide some help. Headers, exhaust work, after market cam, more efficient carburettor, all lend themselves to improving power and MPG when combined properly. Determine your most common driving conditions and determine any upgrades based on those conditions. If you drive mostly highway miles at 2000 RPM or so, select a cam and exhaust option the is designed to operate best within this range.