This truck suddenly quit starting. It has 190K miles. It was running/starting quite well. Getting gas, spark; timing chain looks new. Could it be an oxygen sensor? I tried squirting starting fluid in intake to no effect. You can hear it firing but it just won't catch, it won't keep running. Distributor cap looks new. Any comments welcome. Thank You.
If you have spark, your timing chain might have jumped. To check, pull the plugs, rotate the crank until the timing marks line up. Then see if the rotor is pointing at the no. 1 plug wire connection in the distributor cap. A more accurate way (with the plugs out and the timing mark aligned) is to connect a timing light between the no. 1 wire and ground. Then slowly rotate the distributor back and forth. The light should flash as the cap is moved past the rotor at the #1 position.