89 Iroc conv

I need some detailed info on timing a 305 tpi motor> I know the basics as far as using the timing light and timing tab I just don't know about what to do with the comp. doesn't it control the advance

91Z-28

When you set timing on a CC car you are just setting base timing. On TPI cars the computer is always assuming a base timing of 6 degrees and it makes adjustments from there. So if your base timing is anythign but 6 degrees you are "lying" to the computer and the timing will be off. Set the base timing to 6* and you will be fine.

89 Iroc conv

does the timng of the distributer affect the firing of the injectors. the video that 91Z-28 has posted on zippy videos is awesome cool car.

91Z-28

No, the distributor only controls spark.

RednGold86Z

You have to disconnect the EST Bypass wire to set the timing. It's a Tan w/black stripe wire and has a single weatherpack connector on it, near the AC tubes that come out of the passenger side firewall in the engine compartment. When disconnected, the ignition module fires the coil automatically, without the computer. Set the base timing to 6°. Then turn car off, reconnect wire, disconnect ECU fuse (near battery, along side of radiator on a 89 GTA) for 20 seconds, reconnect (this is necessary to clear the fault code for running with disconnected EST bypass). Check timing with all things connected, and it should be about 20°.