I'm setting the timing on a 1988 firebird 5.0L 305 fi.
I have adjusted timing on other cars and trucks but this engine is a bit different. Maybe you guys can fill in the blanks..

Get engine up to operating temperature
Shut engine off
Mark scribed line on harmonic balancer pulley with white out or paint pen to show line better
Disconnect something ??
Loosen distributor timing bolt
Attach timing light to battery and plug wire #1 (drivers side front)
Start engine
Adjust to 8 or 0 (on the before side)
Tighten bolt
Grab a beer

So mainly I need to know the bolt size ... 9/16?
And do I have to unplug a wire connector before setting the timing? I see two wire harnesses connecting to the bottom of the distributor.


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Ya,,,okay...gran me a cold one.

Loacte the EST bypass connector...single wire connector (on my 89 IROC, over by the pass side wheel well)

Okay...disconnect that plug, start the car, shoot the light at the HB and mark

TPI spec is 6 BTDC...no idea about TBI..

So once timing to spec. shut the car off, plug in the Bypass connector, tighten down the hold down,,,go for a ride.

 

So timing is somewhat set lol. I could hardly see the timing numbers and set it to 4 btdc. So i will reset to 6 tomorrow. The engine is a TPI. I had to disconnect the brown wire and used a crows foot wrench which was 9/16. Now the engine runs way better, it was past 0 atdc.

My friend messed with the idle screw so I had to throttle up the engine a tad to see the timing line. It idles around 500 rpm.

I might set the idle up to 800rpm?

 

Whats going on fellas. I'll sum it up. 91 305 TBI. I pulled the distributor in order to drop the tranny for a quick rear main seal replacement. While I was there I replaced the oil pan gasket so I had to turn the engine. Note; distributor out, however I did mark it. I put it all back together and attempted to start it up but will only crank with a-lot of back fire and spit ups with the occasional flame from the tbi. What's next???

 

Lift the dist until it clears the cam gear; rotate the shaft EXACTLY 180°; drop it back in; try again.

 

I would also set the engine to tdc on cylinder #1 and check to make sure that the rotor is pointing to number one plug wire on the cap.