PWM idle, spark table questions

[coyoteboy]

Starting at
1)
PWM idle. Most of the settings are fairly self explanatory, though very hard to get right. BUT, since PWM closed loop doesnt work during cranking or the ASE period, is the cranking dc the dc used while ASE is active - so setting that should give me my max revs at initial startup? ASE on mine goes on for about 30 seconds meaning my engine is reving its crackers off for 30 seconds - whats the average ASE period? Should i be concerned with idle advance settings and if so can someone explain the proceedure for setting it up?

2) Spark table - im trying to set up my ignition. After getting the thing to run (just to check the VR input worked ok) I found the basic table i had botched together was WAY to advanced as i had expected and since i had taken a wild guess at the trigger angle and it worked I now want to do it properly obviously.

Are the figures in the spark table bins the advance on base or the total angle. I.E. On my stock ecu I had to bridge the diag terminals and use the dizzy to set it to 10btdc. So if i set all of the spark table values to 0 and play with my trigger angle and timing light and get it back to the 10 marker am i doing this right, or should i be setting 10 in the tables bins and then adjusting the trigger to get 10. I know that in essence it doesnt actually matter but I'd like to do it right for ease of discussion in future.

[snillet]

1.

This one is giving ME a headace..., the PWM idle control is also active during warmup. That doesn´t fit my TBI at all since the mixture becomes leaner when the PWM valve opens i get baaaaad hunting after cold start on that setting.

Warm, on closed loop running it´s very nice, but i cannot USE that setting since the cold properties doesn´t work then .

I would need a warmup function that works as "warmup only" and then closed loop PWM control on warm engine.

[coyoteboy]

surely that could be coded up fairly easily - I think im gonna start learning the coding side of it

[jsmcortina]

This one is giving ME a headace..., the PWM idle control is also active during warmup. That doesn´t fit my TBI at all since the mixture becomes leaner when the PWM valve opens i get baaaaad hunting after cold start on that setting.

Something must be wrong with your install then. The PWM idle opening is only equivalent to the throttle opening. In a speed-density install the kpas will rise and more fuel will be injected to compensate.

On the spark table, the commanded value in the table is the actual advance you see at the crank. If the Megatune gauge shows 17deg your timing must be 17deg BTDC.

James

[coyoteboy]

Thanks James, that cleared the sparks up for me, so i'll fill it full of 10s and set it to 10 on the crank as standard. Good stuff. Its all coming together nicely (rubs hands together and cackles manicly)

[snillet]

Something must be wrong with your install then. The PWM idle opening is only equivalent to the throttle opening. In a speed-density install the kpas will rise and more fuel will be injected to compensate.

James

The PWM idle valve takes air from the air-filter box. Then it puts it into the inlet manifold AFTER the injector. On cold starts this means that i would need a compensation for the amount of air that the mixture is leaned out with when the valve opens.

It´s like having a variable air-leak after the injector.

Yes i´m climbing in kpa:s when this happens, but the amount of fuel that is being passed into the manifold is delayed when the valve opens because the air is being put into the manifold AFTER the injector.

I have an ongoing projekt to move over to port injection instead of the Solex TBI i have now, much because of this issue. I can mention that i have 2 cars with the same magnetimarelli/solex setup and BOTH have a tendency of hunting ilde after cold start also with stock ECU . So i guess we can say that the italians made a crappy job with this one

But i´m running the "warmup only" setting now and that works like a charm, just that i do not have the fine rock steady closed loop idle that i want.

Which ...really, is kind of cosmetic anyways... but still

[RNash]

Yes i´m climbing in kpa:s when this happens, but the amount of fuel that is being passed into the manifold is delayed when the valve opens because the air is being put into the manifold AFTER the injector.

I'm confused about this statement. What difference does it make to the MAP sensor where the injectors are? On my TBI, when there is an air leak (PWM idle valve) the RPMs go up immediately.
Maybe your throttle plates are completely closed and restricting the fuel that can get past them?

[snillet]

Yes i´m climbing in kpa:s when this happens, but the amount of fuel that is being passed into the manifold is delayed when the valve opens because the air is being put into the manifold AFTER the injector.

I'm confused about this statement. What difference does it make to the MAP sensor where the injectors are? On my TBI, when there is an air leak (PWM idle valve) the RPMs go up immediately.
Maybe your throttle plates are completely closed and restricting the fuel that can get past them?

It´s adjusted to factory setting, there´s a "leak" slot on it for the purpose.
The fenomena is not as bad on gasoline as on E85, E85 is really "tickelish" the first minutes before the engine gets a little hotter.

I belive there is some kind of fundamental system design failure on the hardware front since, as i said earlier, the hunting on cold dilemma occours also with stock ECU on 2(!) identical engines on gasoline.

[PSIG]

Silly question - is your ASE setting on Normal MAP or Fixed MAP?

David