How do you adjust timing 1989 Chevy truck?

Answer 1

1. You will need a timing light.

2. Find the grove / notch on the crank shaft pulley

3. Make it with white paint or other white stuff.

4. Find the timing tab with the degrees marked on it. It's usually a piece of metal about 1/2 inch with numbers on it. wipe it clean to read it. should have marks 0 to 8 degs.

5. The tab is normally at the drivers side of the engine, on the front, by the side or slightly behind the Power Steering pump.

6. Find the paper label giving the timing spec. In the engine compartment somewhere.

Or Get a Service manual for your truck.

7. loosen the Distributor Hold down bolt and clamp, only enough so you can twist the distributor.

8. Find the single brown wire and connector to disconnect the computer control of the distributor.

It will be a single brown wire with a male and female connector. It will one of two places only!!

A. On the firewall above and to the left of the Dist. It will be hanging out of the bundle. If you have black plastic dust cover over the terminal block, remove the dust cover, that brown wire may be hidden behind it.

B. Peel the carpet back on the passenger side, You may see brown wire and connector there.

9. Warm up the truck, turn it off and connect a timing light to Spark Plug wire number one.

10. Disconnect / unplug the brown Dist. Control wire. The distributor is no longer under the control of the Truck's computer.

11. Restart the truck and shine the light on the timing tab. Compare to Spec's and slightly rotate distribute, clock wise or counter clock wise until Timing Spec reading is obtained.

12. Turn off Motor, Carefully retighten the Dist. hold down bolt.

13. Restart motor and check timing again to Specs.

If all is OK, Turn off Motor, disconnect timing light.

And, And, And replug in the brown wire to put the distributor under Computer Control.

Do not attempt to measure or check timing with the computer engaged. The computer has a mind of it's own for the engine.