Timing Spike @ WOT on Nitrous Oxide
04-04-2009, 01:49 PM
#1
Timing Spike @ WOT on Nitrous Oxide More wacky problems from this same car that will not return to idle routines 100% of the time.
Here's the latest. We took it to the track and were doing some nitrous shakedown passes on a small shot. He made a pass and burned off all but 2 of the straps on the plugs. I look at the log and at about 6K RPM timing jumps from the flat commanded 13* to a solid 29*. First thing I checked was to make sure that there was no modifier table screwing me up. The IAT sensor is tricked to read 73* temp all the time. ECT temp was solid 190-205*. TPS read 100% throughout the entire pass.
There are only 3 tables that show 29* timing in that region of cylinder airmass (0.80 and up). The park and drive idle tables and the max torque table. Only the torque table goes up to 8K RPM. I changed the torque table to 14* and the idle tables to 12* in order to see which one it is. We changed plugs and did a few blasts on the street but it never fluctuated from 13*.
How does this max torque timing table work? Is there a way that I can identify which table is in use while scanning (besides what I already did)?
This is a 99 F-body tuned in Open loop MAF w/ HPTuners. It is a wet direct port shot.
Here's the latest. We took it to the track and were doing some nitrous shakedown passes on a small shot. He made a pass and burned off all but 2 of the straps on the plugs. I look at the log and at about 6K RPM timing jumps from the flat commanded 13* to a solid 29*. First thing I checked was to make sure that there was no modifier table screwing me up. The IAT sensor is tricked to read 73* temp all the time. ECT temp was solid 190-205*. TPS read 100% throughout the entire pass.
There are only 3 tables that show 29* timing in that region of cylinder airmass (0.80 and up). The park and drive idle tables and the max torque table. Only the torque table goes up to 8K RPM. I changed the torque table to 14* and the idle tables to 12* in order to see which one it is. We changed plugs and did a few blasts on the street but it never fluctuated from 13*.
How does this max torque timing table work? Is there a way that I can identify which table is in use while scanning (besides what I already did)?
This is a 99 F-body tuned in Open loop MAF w/ HPTuners. It is a wet direct port shot.
04-05-2009, 05:09 PM
#4
Here's the tune, and a log. As stated above, this is the modified tune in which I changed the Idle Spark tables and the MAx Torque Timing table to 12* & 14* in order to see if these were the tables that I was getting into and figure out which one. All fields currently at 12* & 14* on these tables were at 29* at the time that this log was done. It is also commanding idle/part throttle AFR (stoich).
04-05-2009, 07:57 PM
#5
Since I am running in Open Loop, can I change the OLFA table in the WOT MAP area to match my PE commanded fueling? To clarify my question, do the PE table and OLFA table work together or independent of each other? So if the OLFA table is set at 1.18 and the PE table is set at 1.18, will I end up commanding 12.45 or 10.55?
04-05-2009, 08:19 PM
#6
I thought it would command which ever is richer of the two. I posted in your HP Tuners thread, did you notice the TPS voltage change right before the timing gets jacked up? 4.82 to 4.80. Is it grounding out somewhere? I'd follow the tps wires to see if that is your problem.
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04-05-2009, 11:12 PM
#8
I thought it would command which ever is richer of the two. I posted in your HP Tuners thread, did you notice the TPS voltage change right before the timing gets jacked up? 4.82 to 4.80. Is it grounding out somewhere? I'd follow the tps wires to see if that is your problem.
04-06-2009, 12:06 PM
#12
Max torque timing is for engine torque calculations used for TM.
I don't think this has anything to do with TPS voltage. It is back and forth between 4.80 and 4.82 the whole time. I wouldnt call that a short by any means.
I would at least try setting the OLFA table to something else in the 95 and 100 KPa rows. Something different from your PE value so you can see which if either it is using.
And try setting the whole 4800 column in your idle spark table to 12 instead of just the higher airmass rows.
And even if that worked, it doesn't fix what is happening but it will be alot safer when it does.
I don't think this has anything to do with TPS voltage. It is back and forth between 4.80 and 4.82 the whole time. I wouldnt call that a short by any means.
I would at least try setting the OLFA table to something else in the 95 and 100 KPa rows. Something different from your PE value so you can see which if either it is using.
And try setting the whole 4800 column in your idle spark table to 12 instead of just the higher airmass rows.
And even if that worked, it doesn't fix what is happening but it will be alot safer when it does.
Last edited by JonCR96Z; 04-06-2009 at 06:33 PM.
