how do u adjust the timing on an 89 rs 305 tbi?

 

Warm engine to normal operating temp. Disconnect the brown EST wire sticking out of the harness in front of the blower motor. Loosen distributor hold down. Start engine and check timing. Stock is 0*, most people are running around 4-6* BTDC on LO3's, you'll have to experiment to find what's best for you. Once you have the timing you want, snug the hold down bolt and make sure the EST wire is reconnected.

 

go buy a timing light and have someone show you how to use it, and then do as andy said.

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'86 IROC 5-speed
305 LG4
edelbrock performer rpm intake
edelbrock 600 cfm carb
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'95 3.23 rearend
hotchkis rear suspension