LS3/LS7 Maf sensor dropping signal at wot
03-24-2014, 08:02 PM
#1
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LS3/LS7 Maf sensor dropping signal at wot Hey everyone,
I just installed an LS3/LS7 card style maf sensor into my camaro. The car is a 1999 H/c/i ls3 stroker 6 speed car with 42lb Ford green tops. I am using the Banish injector data for the injectors. I just recently installed this new sensor as I had been running solely in SD and decided to put a MAF back on the car. I also put a screen before the MAF to ensure the sensor is reading a straight airflow path.
As I began tuning the car I rechecked my VE tables and everything was fine and the car ran as it should. Switched over to the OLMAF tuning, part throttle appeared to be ok. As I began working my way up to WOT stuff I noticed rather apparent hesitations through the rpms range and thought it was solely due to the new MAF needing to be recalibrated. I continued to make adjustments and felt I was getting closer and closer. I reviewed some of my logs and noticed I was now getting 4* of knock retard when at WOT (which was not present in the VE tuning), the MAF signal is dropping randomly and the injector duty cycle appears to be following the activity of the MAF sensor.
Here is a log of a quick WOT blast in 3rd gear to give you an idea of what's going on. By the way all the wiring for the new sensor is soldered. Please take a look at the log and tune and let me know what you guys think may be my issue.
Thanks!
Since scanner configs here is the link to the exact same thread on the hptuners board.
http://www.hptuners.com/forum/showth...-signal-at-wot
I just installed an LS3/LS7 card style maf sensor into my camaro. The car is a 1999 H/c/i ls3 stroker 6 speed car with 42lb Ford green tops. I am using the Banish injector data for the injectors. I just recently installed this new sensor as I had been running solely in SD and decided to put a MAF back on the car. I also put a screen before the MAF to ensure the sensor is reading a straight airflow path.
As I began tuning the car I rechecked my VE tables and everything was fine and the car ran as it should. Switched over to the OLMAF tuning, part throttle appeared to be ok. As I began working my way up to WOT stuff I noticed rather apparent hesitations through the rpms range and thought it was solely due to the new MAF needing to be recalibrated. I continued to make adjustments and felt I was getting closer and closer. I reviewed some of my logs and noticed I was now getting 4* of knock retard when at WOT (which was not present in the VE tuning), the MAF signal is dropping randomly and the injector duty cycle appears to be following the activity of the MAF sensor.
Here is a log of a quick WOT blast in 3rd gear to give you an idea of what's going on. By the way all the wiring for the new sensor is soldered. Please take a look at the log and tune and let me know what you guys think may be my issue.
Thanks!
Since scanner configs here is the link to the exact same thread on the hptuners board.
http://www.hptuners.com/forum/showth...-signal-at-wot
03-27-2014, 04:19 PM
#2
I don't have HPT, but I am also swapping out my flow-thru style maf(from 2005 LQ9) for an LS3 card style MAF.
If you notice, the LS3 MAF frequency is much different for a given airflow vs the LS1. example, when your car is consuming 400g/s, the ls1 maf would report~12K Hz, but the LS3 actually reports ~9K Hz. Since the LS3 is reporting 9K hz, your tune thinks it's getting 200g/s.
This may be whats causing the issue, I hope this helps.
If you notice, the LS3 MAF frequency is much different for a given airflow vs the LS1. example, when your car is consuming 400g/s, the ls1 maf would report~12K Hz, but the LS3 actually reports ~9K Hz. Since the LS3 is reporting 9K hz, your tune thinks it's getting 200g/s.
This may be whats causing the issue, I hope this helps.
03-27-2014, 11:06 PM
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You might want to have a look at the ENG_SEN +12V
feed during all of this, just to know whether there is
more of an electrical issue than just the MAF. You could
feed it through a resistor divider to your EIO cable (if
you have that version).
Helm manuals mention that the MAF signal can be messed
up by EMI from other harness signals. Debundling the MAF
signal from the harness I think is the suggested diagnostic.
feed during all of this, just to know whether there is
more of an electrical issue than just the MAF. You could
feed it through a resistor divider to your EIO cable (if
you have that version).
Helm manuals mention that the MAF signal can be messed
up by EMI from other harness signals. Debundling the MAF
signal from the harness I think is the suggested diagnostic.
