So I have been scatching my head as to y the haltec L1 idles/runs and is tuned in the BTDC range? The stock timing is at -5ATDC...(T1 -20ATDC)

I have:
- confirmed my zero idle (locked)
-confirmed idle to haltec map (unlocked@20BTDC)

A am happy that everything lines up between the map and car but, the car doesn't idle at the stock marks...??

Anybody shed some light on this?

 

if you want it to idle on the stock marks you just set it to -5 in the maps

 

Only when locked.

Y doesn't it idle on the marks when unlocked? Would that not be the best timing for idle?

 

+5 degree idling for me at 900RPM ~14 AFR with IAC walve.
I have ported 13B cosmo engine and 850/1680 injectors.
At -5 degree I have smooth idling but AFR is ~12.5 and car stalls after I lean fuel to 13+. The yellow mark is for -5 degree leading.

 

it doesnt idle on the marks when its unlocked, because thats not how you have the ignition map set.

 

The marks on the pully are for aiding in the synchronization process with the Haltech so that you are 100% certain that what ever the haltech is spiting out as timing will be on the engine. Normal timing values arent that far though, normally you'd see 5 degrees at idle, which would be about 10 degrees away from the leading mark, so if you look at your ignition map at that load and rpm point you'll prolly see thats where the haltech/engine are sitting at.

 

Let me elaborate, I'm all lined up, if I lock to -5 I get -5. I noticed my map is at 20BTDC , It runs lower if I retard it even closer to what mazda's -5 is. I get my highest rpm at 20BTDC? Maybe something is going on or is this normal?
Stock port S5

 

Something you have to take note of, if you talk about the marks on the crank pulley, they are located at 5 and 20 degrees AFTER Top Dead Center, which is the same thing as saying -5 or -20 Before Top Dead Center.

Under normal circumstances, 13B's like to idle on or about 5 degrees BTDC, which is about 10 degrees before the leading mark.

If your ignition map, or leading timing value is flatlined at 20 degrees (BTDC) you should see 20 degrees on the crank pulley, but this is on the opposite side of the red 20* ATDC trailing mark, if you're seeing something else, then you may still not have lined it up correctly, or your trigger angle and tooth offset, or even trigger edges might be incorrect.

Whats the problem you are actually having?

 

I guess if I can't understand something it is hard to move forward. I do have a slight miss down low and was hoping it was related to the timing.
Not seeing anything different, car just doesn't idle as well where stock one does.

Someone please go out to thier car and set idle to 20 BTDC then lock it @-5(or lower it to zero) and tell me if I'm crazy that it runs at a lower rpm.

 

You are correct, I just tried it, lost 400 rpm (1100 - 700) The engine runs a lot smoother though.

 

Thanks for checking.

Looks like my question still stands..I thought the higher the idle the better it was timed...oh well.

 

I went for the middle ground...8-10BTDC

 

Is that the idle the computer is spitting out with timing map at zero?

if it is a map someone has set for you it is quite likely that with the base timing locked at 5 after to match the fatory leading mark that when running it will be 5-10 deg BTDC.

Running this timing allows you to use less air and run a lot leaner. So if you just wind it forward with the same air and fuel the idle speed will increase

for example on a stock 12a with caby/dizzy if you wind in 10-15 deg advance on the dizzy you have to drop the throttle stop back a few turns and you can back off the air bleed and take out heaps of fuel with the idle fuel screw and still idle real smooth from as low as 600rpm.

 

just to clarifiy the crank pully is 5 and 20 AFTER top dead center, NOT before.

if you lock it on -5 and its on -5, then when you unlock it, it should go to whatever value is in the ignition map +/- any corrections.

20btdc is a lot at idle, stock its -5btdc, and it seems like anything around stock to about 10btdc is good, either what makes the engine happiest or passes smog.