What base timing???

dogdays · October 30, 2001

I thought it was posted before but cannot find it, so here goes again.

I have a 93 Suburban K2500 5.7. I would like to know what base timing has been found to be best for power/mileage. We take it on long trips, lots of 80mph driving, so a small percentage gain in mileage would help. I don't have a scan tool to check out the knock sensor reading.

So keep it at zero? 4 BTDC? 10? what worked for you?

Thanks,

r. ???

dogdays · October 31, 2001

BTT I checked mileage last night, I'm down 1.2 mpg. Time to go to smaller advance!

R.

76BBSub · November 1, 2001

On a computer controlled vehicle like yours I would just run the factory base timing, maybe up to 4 degrees additional advance but no more.

There's a thread in the Classic Forum where we are comparing timing settings, initial, mechanical, vacuum, etc. Check it out for a comparison.

Jeff

dogdays · November 2, 2001

WOW, Maybe I expected too much from the board.

I got more at a site dedicated to third generation Camaros, they are actively pursuing TBI engine development. There I got +4 degrees, maybe 6. I will try 4.

R.

Heavy Cruiser · November 2, 2001

Check the emissions sticker, onthe hood, fan shroud, or radiator support. Probably will read 6 BTDC with timing connector disconnected.

Timing connector, some say is located under heater on pass side, some trucks are in the eng compartment.

Turn off eng, unplug, start engine, set timing w/timing lite, turn off engine, remove t/lite, plug timing connector together, unhook battery to erase codes, reconnect battery.

Take measurements again for mileage.

November 2, 2001

Quote from dogdays, posted on Nov. 02 2001,11:01

WOW, Maybe I expected too much from the board.
I got more at a site dedicated to third generation Camaros, they are actively pursuing TBI engine development. There I got +4 degrees, maybe 6. I will try 4.

R.

Maybe you did expect too much. I don't think anyone hear should or will advise you on changing the factory settings of a computer controlled ignition.

That could cause a number of problems for you and for the webmaster.

What if I told you to run 6 degrees advance and you burnt a piston? Who's faul is it? Mine, yours, or Mervz'?

You can get a lot of good info here and at other sites, but a lot of folks just spew nonsense. You have to be careful what advice you give and what advice you take.