I have a 92 305 tbi completely stock with the exception on eldebrock headers, I went to set the timing the sticker under the hood says it should be timed at 0 degrees BTC (idk what BTC is) it idles a bit low but timing wouldnt effect that too much, it runs okay but seems to be a little sluggish, the timing teeth in the picture below, doesnt have any marking on it to tell me which tooth is what degree so idk where to time it, and ive also been seeing that they run really well at 6 degree BTDC so id like some opinions on where i should time it, and if anyone knows the timing on the teeth it would be appreciated thanks

 

The biggest toothe is 0. I like to run a stock L03 at 6 btdc. I normally run an advanceable timing light. But I think its the 3rd toothe?

 

so the biggest tooth is the one all the way to the right? and then 6 degrees is 2 teeth to the left?

 

I hope someone chimes in. I dont have stock damper or cover on mine anymore I'm more going on memory

 

Where it is now is 4* BTDC. See picture in this thread:

https://www.thirdgen.org/forums/tpi/...c-diagram.html

RBob.

 

Way to go!

 

I have posted this before but feel I should post it again just in case someone dose not know that you have to have the EST wire unhooked to get your base timing mark.Thats what we are working with when setting timing.
I found this on a old thread concerning timing. Here's how they said to set it and a photo of the EST connection.=
Disconnect the EST wire, start car, adjust timing, shut off car , reconnect EST wire.

 

You may already know this but if your car has "spark knock" under load or at any time at 6* you must turn the timing down to lets say 4* using the same procedure out lined in post above. Best to just carry your timing light and tools around with you for awhile.

 

So lets say i turned my distributor on accident without disconnecting my EST wire, How bad necessarily is that lol, When i fix my timing (its off right now) should i fix it with my EST still hooked up then try to fix it again with it unplugged?

 

Warm up engine, shut it off, unhook connector, restart, time it , tighten down distributor, recheck after tightened, shut off, hook up again, done

 

https://www.thirdgen.org/forums/tech...photo-2-a.html

 

Thanks, I'll get a timing light and do it up sometime soon.

 

Since we're on this topic, I have an '88 IROC TPI LB9. I've added a 255gph fuel pump a while back, high flow cat and Flowmaster catback all 3". I feel it's running pig rich; should I advance the timing to 8*-10* instead of the 6*? Any other suggestions?

 

From what I understand advancing base timing simply applies to when the spark is ignited during the compression stroke. I don't think it has much to do with running rich. I may be mistaken.

 

well you have a tpi engine we are tbi guys over here. but I dont think advancing the timing a few degrees wouldnt hurt either way. but it probably will not fix your problem. you have may have too much fuel pressure. do you have teh adjustable regulator on it? that may be an option. The best bet is to post your problem on the TPI section of this site and see what they have to say.

 

so did this ever get fixed.

 

I just did this. Ended up with around 6 degrees advanced for the sweet spot. When advanced too much it would have idling problems at startup or sitting at a lights so I just backed it off a hair until it ran right.

 

I tried setting my timing to 6* advance and then 4* advance and it just ran horribly so I set it back to base 0* Runs great now

 

305 chev timing teeth numbers
I just done mine as it was way out at 12° as the dizzy was loose and moved.
So from right to left inbetween first and second notch. 0,2,6,8,12 mines at 6°

 

interesting ....carby ?

 

Stock TBI heads are fast burn by design and do not need any advance built in to the base timing. TPI is different.

 

...reconnect/hook up EST connector, CLEAR THE CODE you created by running the engine with the EST disconnected. Done.