if any of you have read any of my previous threads, i am working on a motor that was overheated<br />(slightly, according to the owner/friend.)and has had zero care in five years.<br /><br />she has been given a new impeller, stats, plugs and a new rectifier.<br /><br />on the test run she ran and idled great, but the owner took his family out last weekend and the motor had a slight surge while being held at a steady throttle position after about 30 gallons of fuel. (and then he bought marina fuel. d.a)<br /><br />i removed and cleaned the oxygen sensor (and ports) last night and it failed both tests in the manual ie. 5 ohm reading on the heater and no output voltage when the tip was heated slightly. (rodbolt warned me that this 'test' was inconclusive.) the ceramic looked clean an the passage was only about 10% blocked. i hate to condem the o2 sensor, but are there any other tests thay can be performed before i make him buy one?<br /><br />the motor needs a de-carb job. the fresh plugs are chunky from the weak dose of sea-foam. a couple plugs even showed wet after sitting for a few days. i'm going to run some valv-tec thru it tonight with the old o2.<br /><br />so. are there any other methods to test the o2 sensor besides throwning it down in the driveway and running over it?<br /><br />after decarb, should i invest in the diagnostic cord so money won't be thrown at the throttle position sensor and the other electronic gizmos. moi believes the surging is fuel pressure/clogged screen related, but i like to change just one item at a time when i'm working on other peoples toys.
