Total Timing

[SmokeShow]

I'm not lokoing into theory or anything. Just got a question about which tables make up total timing for pilot and main inj?

When I log the pilot inj timing PID, which table is it logging?



Looking through some logs last night makes me think efi live works a little backwards (or I should say, I see it backwards) sort of to get the actual "start point" of the injection event... Ex.: lets say Main Inj Timing was at 20*. Looking at the timing table for Post Pilot Inj. Timing and it says 12*. That means (or so I think) 12* after the pilot inj. fires the main injection will fire. Not seeing a table that says when pilot inj. starts, I'm thinking it takes those two values (20 and 12), adds them together (20+12) and figures the actual pilot inj. start time that way? Giving 32* of total timing.


Is that right??? or am I off base???



C-ya

 

[malibu795]

I'm not lokoing into theory or anything. Just got a question about which tables make up total timing for pilot and main inj?

When I log the pilot inj timing PID, which table is it logging? when loging pilolt inj it looks at one of these 4 table B0926-b0929 thECM changes tables bases on engine coolant temp


Looking through some logs last night makes me think efi live works a little backwards (or I should say, I see it backwards) sort of to get the actual "start point" of the injection event... Ex.: lets say Main Inj Timing was at 20*. Looking at the timing table for Post Pilot Inj. Timing and it says 12*. That means (or so I think) 12* after the pilot inj. fires the main injection will fire. Not seeing a table that says when pilot inj. starts, I'm thinking it takes those two values (20 and 12), adds them together (20+12) and figures the actual pilot inj. start time that way? Giving 32* of total timing.
thats the way i figure it me personally i try to keep total timing under 40*. on WOT the pilot INJ is turned off

Is that right??? or am I off base???



C-ya

you can controll when pilot is on and off with table B0748 pilot injection quanitiy

 

[stacks04]

okay so why then does gm use timing after pilot d and in the upper range before pilot gets shut off the timing to wait is like 30*. like smoke show i asked this before. i am confused to the unteenth degree with timing. if i change my main from say 15* for say 20*main timing, and the pilot is on, the b0929 is calling for 12* after pilot. does it start the pilot pulse earlier to compensate the earlier main timing. i would think so.

then you (malibu)said you keep total timing under 40*. total timing in the main table? i don't see where you would add to that except your multipliers

 

[malibu795]

total timing for me is main+pilot= total... when i do a timning table i set pilot to 10* and keep main ijnection under 30*

i agree with you.. if you increase main timing liek you said form 15 to 20 and pilot stayed the same and pilot was still 12* the injection would start are 32* veses 27* BTDC

as for multipliers usually that is when the engien is NOT in side a set operating parameter IE cold under 160* or HOT over 240* is when the ecm pulls timing and fuel to reduce power

 

[sweetdiesel]

I agrree with what Adam said

some things to keep in mind are max timeing table,If you set this table at 40* And your pilot is say 25 and main is 25* it will pull timeing from the main inj timeing to =40*.....this is something to keep in mind if your timeing doesnt add up

remember as Adam allready said though Pilot inj timeing should be off at WOT
quantity is one way to shut it off there is also a varible you can change to make it shut off also when it drops below a certain #
one thing i like to do when viewing pilot quantity is make the table 3 decimal places

 

[SmokeShow]

so if I were looking at a WOT log and I had PID PIINJTIM and MNINJTIM and they were both at 30*, that is 60* of total timing?

NOW... However, if I have my pilot injection quantity set to 0 at WOT, then no fuel (in theory) is actually started to be injected at that combined 60* BTDC but rather it actually starts injecting at 30* BTDC right??? So that the actual total timing is still just 30*????



I'm also seeing funny spikes in my PIINJTIM values while logging. Certainly higher numbers than what I see in any of the tables B0926-B0929. So, where , exactly, is that PID reading from in the tune???


Thanks folks, this is good stuff!



C-ya

 

[stacks04]

mitch, from what adam said than technically no pilot is not on as long as it is set that way, than you should be only using your main timing. to answer your other part about the spikes you may want to post your log so they can see what it is your talikng about.

thanks adam for clearing that up. the only way to change pilot timing is with the b0926-9 correct? also where do you set max timing parameter. i have looked for it but cant find it. i am stupid so it may be there. thanks guys for helping me clear this up. i have some changes to be made now. to much timing total i some areas.

 

[malibu795]

thanks adam for clearing that up. the only way to change pilot timing is with the b0926-9 correct? also where do you set max timing parameter. i have looked for it but cant find it. i am stupid so it may be there. thanks guys for helping me clear this up. i have some changes to be made now. to much timing total i some areas.

yes on pilot

B0921 is inj max timing. this set teh limit for mian injection timing and does not touch pilot timing.. AFAIK there is no table limiting pilot timing maximum outside the said pilot tables which is -/+45*

some trucks are limiting 20* from the factory others 30* i set all mine about 35-40*

 

[stacks04]

B0921 is inj max timing.

okay right there in front of my face. told you i was as dumb as i sound:baby:

 

[malibu795]

thank god i cant hear words :rofl: :rofl: :rofl:

 

[stacks04]

nice. yeah okay i changed it because it was set to 40 down low but only 20 from 1500 and 20mm3 on up.