Vehicle: 1986 Nissan Pulsar NX Canadian Model
One of the problems i have is bad gas mileage, between 9 MPG to 13 MPG ish. That kinda sucks. New distributor cap, rotor, spark plug, plug wires, carburetor fully rebuilt and refurbished, tightened up power steering and replaced alternator belt.
I notice that the car is louder than what a car should be (bought it used). and, the idle is unsteady when the car warms up (jumping around
875 - 1000). The engine is also unsteady and sounds like it misfires when hot in park or neutral (around 1200RPM) no load on the engine. Put it in gear it drops to about 875 and jumps around. I turned the idle up to that speed because it will just stall out if i didn't raise it up.So can a bad muffler cause this? I also noticed that when parked close to the house or a wall or beside another car, there seems like an exhaust noise is coming out from under the car and reflecting off the wall. So exhaust leak is possible, and i've heard that an engine needs backpressure to operate efficiently.
Could anything like this be the probelm? EGR valve maybe?