Darren1

I am having some issues with my 89 TA that had a 383 stroker TPI when I purchased. My son messed with the timing and now I am having issues. This motor is higher compression with many aftermarket parts from bigger runners, larger injectors and a not factory cam. I am not sure what my can actually is. My question is what would a good starting point be for setting base timing ? I have it at 8 deg. now but it feels like I am still short on the power it had as well as it now has to crank over a few revolutions before it will fire. It use to fire almost instantly??? I am not familiar with how a stroked motor affects timing if at all. TDC is still TDC ?
Thanks

88gta3508

Still using a TPI system? Do you have a tune??? If not you have a large cube build, Cam & Inj. Trying to run on a factory tune! 8 deg is a start. You need to unplug the est connector. Also need this burnt into the Eprom.

Darren1

Thanks for responding.
Yes I am using TPI. I after playing with it have it at 12deg. I decided my problem is that it had no thermostat. I would get good and warm in garage. Set Timing, IAC TPS and it would run fine and idle nice. ( just a little choppy) But as I would take it out to test drive it would cool down and go back into open loop and that is where I was having problems. I plan to put a T stat back in the car and go from there. It had a tune on the chip when I bought it.
I wish when I first got it and it ran perfect I would have put a timing light on it to know where it was set.
Thanks again.

RazorN8

Just got done putting a 383 in a 1987 Camaro. Mine is pretty wild with the cam and heads I used, and it really liked a lot of base timing. It would do the same thing as your describing when I put a standard Distributor in and set timing around 10 degrees. I ended up limiting the amount of advance (non-computer controlled anymore) and setting base timing at 18*. It fires right up and idles well now. For some reason, the 383s like their base timing. I limited my advance to 38* all out though.

Darren1

Thanks, 18deg base timing with your est connector un plugged ???

AlkyIROC

Base timing really depends on the cam grind and the computer needs to be disconnected by unplugging the EST to set it. Without knowing the grind, it's hard to give a proper suggestion. Either way, once base timing is set, total timing needs to be limited to where the engine likes it the best. That can be anywhere from 28* to 45* but generally a NA engine works well in the 34-38 range.

If you original base timing was 8* and total was 38*, moving the base timing to 18* will bump your total to 48*. Since it's computer controlled, you need to get the total reprogrammed.

sofakingdom

iTrader: (1)

You have no idea what the "ideal" timing "number" is, or whether your "mark" is accurate; therefore a "light" and a "mark" and "numbers" and all that, are useless. But it's actually much simpler than that.

You can do exactly 3 things with timing.

You can leave it where it is.
You can retard it.
You can advance it.

Since you're asking this question, I think it's safe to rule out the first option.

The second option usually makes an engine run sluggish, low on power, poor throttle response, runs hot, use more gas. It's also "safer", in the sense that too much advance can cause detonation, but too little just causes... yuck.

The third option is usually the right one. It makes an engine run crisp, have snappy throttle response, good power, its best possible gas mileage, and runs cool. However it's possible to go too far, and make the engine ping and detonate, all of which you must avoid at all costs.

It's pretty easy to figure out what to do. All ya gotta do, is loosen that bolt, turn it a little bit (mark where it is now so you can go back), tighten the bolt back, and go for a test drive. It's not important which way you turn it to start out; just remember which way it was.

When you do that, one of three things will happen.

Nothing.
It will run worse.
It will run better.

You won't often get #1, but in case you do, turn it some more.

If it runs worse, turn it back to where it was before, plus a little bit farther.

If it runs better, turn it a little bit more the same way.

Test drive again. Adjust again. Test drive again. Adjust again. Test drive again.

Keep doing that, following the better/more vs worse/back discipline, until it's as good as you can get it.

See? It's not brain science or rocket surgery, it's just a car. One of the simplest, commonest mechanical products in our lives. You can do this.

Then once you get it as good as it gets, mark it, so that if someone who thinks they're smarter than you comes along and disturbs it again, you can put it back where it was quickly and painlessly. You could even use your "light" to look at a "mark" if that makes you feel better at that point. Usually just a drop of paint at the base of the dist is all it takes though.