In my '85 Tercel, I am getting about 23 mpg when I should be getting about 30. I’ve replaced the air filter and fuel filter.Tires are inflated to the proper pressure. Spark plugs look good and so do the wires. I sprayed some carb cleaner in the carb and turned down the idle. What else should I try?
I guess I am losing backpressure as my muffler rusted off but I dont think that would cause that much of a loss in fuel efficiency.
When you turn down the idle on a carb does it reduce the A/F ratio throughout the power band or just at idle? I’m a newb to carbs.
Where have you been filling your gas up at and does she idle long? Also do you idle her out doors or indoors?
I fill up where ever is closest. No loyalty to gas stations for me. No, I dont let it idle long at all.
Dave, on a carb you’re going to have two adjustment screws.
-
The idle speed adjustment screw.
-
The fuel mixture screw. The backyard mechanic way to tune these carbs that I always read about is to lean out the car while it’s idling until it begins to stumble, then richen the mixture by 1/2 a turn of the screw. Try that - if someone richened the mixture to deal with crappy running problems because they didn’t change plugs/wires, etc., then that should help your fuel mileage.
Excellent! Thanks Kris, gonna try that tomorrow. Stupid non-fuel injected cars!
Meh, no computer to get in the way of the tuning. Try tuning a spec v, where the ECU starts ignoring inputs from the SAFC-II over time and just reverts to its stupid pig rich status.