92lt1

i have a 89 350 tbi that has the following: bored 30 over,flat top pistons making 10:1 comp, 270h comp cam,new lifters,springs ect. i has the stcok ignition and i only run premium. my question is, what should i put my timing at? you can email me if you want at pol340@chartermi.net

lykan

Advance the timing in 2 degree increments until you start to hear ping, then back off until it goes away. Each car is different. Some don;t like any timing while others run at 12+ degrees advanced. Do a search, keyword "timing" and you will see a lot of different ideas.

With the TBI ECM, you have to remove the EST wire. If you don't the computer will correct your timing and you'll never get it right..

92lt1

thanks you sir. brad

88TAJeff

I don't think you'll ever actually get to hear the pinging. I've had the computer pull 10 deg. of retard without hearing so much as a single ping.
I think advancing until pinging is something for the older carb cars that don't have computers.

92lt1

could you give me your suggestion about timing it then, it would be appreciated. thanks brad

88TAJeff

What's stock for a TBI ?

92lt1

sorry i couldnt tell you.

88TAJeff

Well here's a little thing I read on here:
To set your timing based on a vac gauge; adjust timing until you hit max vacuum, then back off 2 deg to allow for detonation.
I did this with my TPI and I ended up with 12 deg. I knew this would be too much, so I set it back to 10 deg.
The car ran excellent with this, but pulls timing out at about 2500- 3000 due to detonation.
The best way is to use a scanner if you have one and check for knock counts.
Or I guess you could always go to stock which I believe is around 0 deg for TBI. I could be wrong
Good luck,
Jeff

lykan

I have a 94 TBI 350. Stock is set to 0 degrees. anything more than 1 degree advanced and the ECM starts to pull timing.

Look above the radiator. They usually have a vaccum diagram on the shroud which has vacuum routing as well as spark gap, and timing.

Your car is not stock tho, so the timing might be a bit different. The best way was as stated by 88TAJeff. Get a scanner and watch knock counts. Timing is usually set to stock by mehcanics, but tweakers trying to get the most power usually advance it until they #1 have detonation or #2 it doesn't perform well.

It really does depend on how well your car runs at a given setting. If you know wha t I mean.