LT1 Camaro $EE running 41 degrees of timing at WOT

**EagleMark** · 09-14-2012

I had some time to look at the surging idle. It looks to need some flatening out of the area like spark for idle. I made the changes so you can compare the difference with the bin uploaded here to yours. Choose the 6-8 cell area around idle and use wire frame to compare, you'll see where one area was a huge difference. The entire table is also smoothed, it will look quite differant then your origanal but changes are very minimal.

Saw your BLM issue right to left. See if the flatened area helps. I use a laser heat gun on headers and adjust Individual Cylinder Fuel Trim (At Idle). If you look through bins they all have differant settings, why I don't know. But they can be opisite in same motor same body style, differant in others, then can be quite differant once again if adjusting based on EGT of header. Something is rich on that one side?

Also don't like the method you used for idle spark, it can cause KNOCK off idle. Again take a look at Spark Advance Main and Extended table in Wireframe view in bin attached and you can see how much better it will respond. Again although wireframe looks completly differant, if you compare the differences and take into effect surrounding cells it's almost the same.

The Main Spark Advance, Extended spark advance and main VE tables can be copied into your bin if you wish. If not just look to learn.

**96lt4c4** · 09-15-2012

Originally Posted by EagleMark

I had some time to look at the surging idle. It looks to need some flatening out of the area like spark for idle. I made the changes so you can compare the difference with the bin uploaded here to yours. Choose the 6-8 cell area around idle and use wire frame to compare, you'll see where one area was a huge difference. The entire table is also smoothed, it will look quite differant then your origanal but changes are very minimal.

Saw your BLM issue right to left. See if the flatened area helps. I use a laser heat gun on headers and adjust Individual Cylinder Fuel Trim (At Idle). If you look through bins they all have differant settings, why I don't know. But they can be opisite in same motor same body style, differant in others, then can be quite differant once again if adjusting based on EGT of header. Something is rich on that one side?

Also don't like the method you used for idle spark, it can cause KNOCK off idle. Again take a look at Spark Advance Main and Extended table in Wireframe view in bin attached and you can see how much better it will respond. Again although wireframe looks completly differant, if you compare the differences and take into effect surrounding cells it's almost the same.

The Main Spark Advance, Extended spark advance and main VE tables can be copied into your bin if you wish. If not just look to learn.

Thanks, getting ready to check it out right now.

The 20* across the board for idle was just an experiment to see if I could help the surging idle, I did not plan to leave it that way. Those spark tables look sweet, I will give those a try. I am going to repopulate "Closed TPS Spark Advance Vs. RPM" with about 23* across the board.

These cars seem to suffer from split BLM's when they are modified. There are posts all over the LT1 sections in most all the forums.

**EagleMark** · 09-15-2012

Originally Posted by 96lt4c4

These cars seem to suffer from split BLM's when they are modified. There are posts all over the LT1 sections in most all the forums.

Yes I know, again look at:
Individual Cylinder Fuel Trim (At Idle) and (Off Idle)

The Sequential part goes away around 3000 RPM and this won't be an issue anymore.

The Idle BLM split drove me nuts, I even pulled injectors once and had them serviced thinking one was weak or one was leaky) and before service Mr Injector does test them. To my surprise they were the best injectors I had ever brought in? That's when I used my Laser Heat Gun I have in AC tools on header pipes at idle to adjust these settings. Big changes when you can change EGT by over 100 degrees! When done BLMs were in order and I expected issues with off idle but nothing...

That spark table was built off your table! So it is fine to use, same with Main and extended VE. Should be a smooth transition to continue the tune. Will run better and will tune better... I wanted you to see what it is you needed to learn. You'd be surprised that I have never seen a mail order tune come with tables built the way all tuning books outline as proper way to build tables...

**96lt4c4** · 09-16-2012

Originally Posted by EagleMark

Yes I know, again look at:
Individual Cylinder Fuel Trim (At Idle) and (Off Idle)

The Sequential part goes away around 3000 RPM and this won't be an issue anymore.

The Idle BLM split drove me nuts, I even pulled injectors once and had them serviced thinking one was weak or one was leaky) and before service Mr Injector does test them. To my surprise they were the best injectors I had ever brought in? That's when I used my Laser Heat Gun I have in AC tools on header pipes at idle to adjust these settings. Big changes when you can change EGT by over 100 degrees! When done BLMs were in order and I expected issues with off idle but nothing...

That spark table was built off your table! So it is fine to use, same with Main and extended VE. Should be a smooth transition to continue the tune. Will run better and will tune better... I wanted you to see what it is you needed to learn. You'd be surprised that I have never seen a mail order tune come with tables built the way all tuning books outline as proper way to build tables...

I will reflash the car with your bin this week and post back how it does. Its funny how some of these mail order tune places get such a good rep. most guys just do not know any better. It does take a long time to learn all this stuff. I have been playing for years and I know just enough to be dangerous....LOL

**EagleMark** · 09-16-2012

I'm not sure about the whole bin? Main VE, Extended VE and spark table are all I did... make sure something didnt get messed up from your bin..

**96lt4c4** · 10-15-2012

Finally got around to reflashing this car last week, and it is doing a lot better. The WOT spark is in safe levels about 33 degrees of timing. The surging is gone, but he said it stopped doing that when it turned cold outside? So I am not real sure if that is fixed or not. Maybe MAF or something with IAT?