Measured timing higher than timing table?
07-20-2006, 08:15 AM
#1
Measured timing higher than timing table? I compared the commanded timing with the high octane table and find out that in the middle load range the commanded timing is 3 - 7* higher than in the table.
Is there a reason? I know that when the EGR is active there is a timing advance, but is it so much?
When I see KR it's always in the region with more timing as in the table, and I was thinking to reduce it by some *. Is that a good idea?
Thank you - Stefano
Is there a reason? I know that when the EGR is active there is a timing advance, but is it so much?
When I see KR it's always in the region with more timing as in the table, and I was thinking to reduce it by some *. Is that a good idea?
Thank you - Stefano
07-20-2006, 10:29 AM
#2
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Let me know what you find out because I had a very similar problem with my friend's '99. We set his timing table to 18* across the board for WOT above 4000 when it was on the dyno. The log showed him starting at 23* and peaking at 26* when we let off. It's almost like the timing change at that part of the table didn't take. 
07-20-2006, 04:10 PM
#3
Originally Posted by SSpdDmon
Let me know what you find out because I had a very similar problem with my friend's '99. We set his timing table to 18* across the board for WOT above 4000 when it was on the dyno. The log showed him starting at 23* and peaking at 26* when we let off. It's almost like the timing change at that part of the table didn't take.
If the low octane values are higher than those in the high octane the PCM will take them. The PCM taket the highest value from both tables.
My timing is fine at idle and at WOT too. It's higher only between 1000 and 2400 RPM.
When the EGR is active there is less oxygen and timing can be rised.
In LS1Edit I can't control that, but I think HPTuners shows this table.
It would be interesting to see what this table makes, how much advance it adds when the EGR is active.
07-21-2006, 06:37 AM
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Originally Posted by tici
OK, this is a guess... but have you changed the low octane table too?
If the low octane values are higher than those in the high octane the PCM will take them. The PCM taket the highest value from both tables.
My timing is fine at idle and at WOT too. It's higher only between 1000 and 2400 RPM.
When the EGR is active there is less oxygen and timing can be rised.
In LS1Edit I can't control that, but I think HPTuners shows this table.
It would be interesting to see what this table makes, how much advance it adds when the EGR is active.
If the low octane values are higher than those in the high octane the PCM will take them. The PCM taket the highest value from both tables.
My timing is fine at idle and at WOT too. It's higher only between 1000 and 2400 RPM.
When the EGR is active there is less oxygen and timing can be rised.
In LS1Edit I can't control that, but I think HPTuners shows this table.
It would be interesting to see what this table makes, how much advance it adds when the EGR is active.