Hello there, thank you for asking about your 1986 Ford V8-5.0L. The throttle body and idle air control valve should be cleaned first. The idle is not adjustable on this vehicle but the throttle stop on the throttle body can...
Adding additional vacuum to the car when it is already backfiring will usually compound the problem due to the lack of fuel supply. Backfiring is most often a result of a lean condition. Adding transmission fluid to the fuel mixture...
