85 S15 Repair Manual
. 375 Answers SOURCE: It has to be done with a scanner.
You can adjust this distributor, but there are no timing marks to watch as you move it. There is a timing mark on the balancer and on the timing cover for referencing Top Dead Center #1 cylinder only, but it is only used for dropping the distributor in to get the engine up and running. A scanner is needed to properly adjust the timing. Connect the scanner and look for a data parameter labeled ‘cam offset’ or possibly ‘cam.’ It will be listed in degrees.
Start the engine, and bring it up to 1500 rpm. Note the reading. If the timing specification is not within plus or minus two degrees of zero, you need to move the distributor.
You can move the distributor with the engine running but the timing will not change. After you move the distributor, the ignition has to be cycled off to let the computer learn the new timing spec. Restart the engine, bring it up to 1500 rpm and see what the new spec is. You must repeat this procedure until you get the timing into the specification as mentioned above. Once you have it set to spec, the code should clear. Posted on May 18, 2008.
85 S15 Repair Manual
Original GMC Repair Manuals.written by General Motors specifically for the year and vehicle(s) listed. Official Shop Manuals that the dealers and shop technicians use to diagnose, service and repair your GMC Sierra, Suburban, Denali, Yukon, Jimmy, Envoy, Sonoma, Acadia, Savana and Safari Van vehicles. A must for anyone who insists on Genuine OEM quality parts.
A factory service manual generally covers General Information, Service Information, Suspension, Driveline, Brakes, Steering, Engine Mechanical, Cooling, Starting, Ignition, Emission Controls, Engine Controls, Transmission, Transaxle, Exhaust System, Fuel System, HVAC, Instrumentation & Warning Systems, Battery & Charging System, Audio Systems, Lighting, Electrical, Body Interior and Exterior and more. A Wiring Diagrams Manual generally covers Connector Repair Procedures, Wiring Harness Overview, Overall Wiring Diagrams, Fuse and Relay Information, Power Distribution, Fuse Details, Ground Distribution, Component Location Charts, Component Location Views, Vehicle Repair Location Charts, Component Testing and more.