recently put together an s10 with tbi 383. Everything is working properly except for the ESC (code 43), is there anyway i can tune this out? maybe subtract the spark bias from the main spark table and then make the bias 0, then uncheck the ESC malfunction flag? This ESC is giving me problems and i would rather just get rid of it completely. The computer is a 16197427, using 0D mask Thanks, Allen

Uncheck the malf code 43

Set the max retard tables to all zero

RBob.

sounds easy enough, do i do anything with the main spark bias or should i just leave that alone? The reason i ask is because my main spark table has a maximum of 30* timing, the spark bias is 9.84 degrees, So how does the ECM know when to subtract out the bias? or does it automatically do it all the time? and because my ESC system is malfunctioning, would it have any effect on the bias?

Also, what would be the best way to add more timing? like i said before, my maximum now is 30* and id like to have around 35* total. Would i add 5* more to it, or would i have to compensate for the bias and add 14.84* (5+9.84)?

P.S. RBob, the reason for the code 33 that i was getting was because i had the MAP hooked to the TB port vacuum like you said, I hooked it to manifold vacuum port and the code went away, so thanks again!

What the ECM does with the spark bias values, CTS comp, main & all is divorced from the ESC system.

The ECM adds up all of the SA values, then subs off the bias'es and initial. Then the ESC comes into play. It can only reduce the timing from that point.

Check out the SA Logic article for the '7747 ECM (Chap 5). It won't be exact for each parameter. But it will describe the basic function of the ECM with regards to SA.

Note that with or even without an ESC system, it is important to understand how the engine reacts to various levels of timing. More isn't always better. Look at the plugs as you make changes to the timing.

It is good that the code 33 was fixed. You can't tune when that code is active.

RBob.

Right now, with 30* total and a 9.84 bais, that takes me down to the low 20*s and that just dosent seem like enough advance for this engine.The engine is a typical 70's small block,383 cu.in. with 276H cam and stock 350 heads. I figure 35* total timing should be in the ballpark of what the engine wants, alot closer than 21-22* anyway. Once i get total timing set at 35*, ill run the truck long enough for the computer to relearn the fuel trims and then ill do some runs and check the plugs and adjust from there.

Ill read the thread you posted, thanks for the info.