LS1Edit issue
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Joined: Jan 2002
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From: USA
Re: LS1Edit issue Yes it will confuse the PCM and the line pressure for the A4.
MAF table took GM a long time of testing to get it correct so I do not suggest the stock MAF be replaced or table mucked with unless it is just a slight tweak in tuning.
There is no way you can test and determine all the correct values to replace in that table, plus have it match injector flow for best performance.
MAF table took GM a long time of testing to get it correct so I do not suggest the stock MAF be replaced or table mucked with unless it is just a slight tweak in tuning.
There is no way you can test and determine all the correct values to replace in that table, plus have it match injector flow for best performance.
11 Second Club
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Joined: Sep 2002
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From: Albuquerque NM - The Land of 8000ft DA
Re: LS1Edit issue
Yes it will confuse the PCM and the line pressure for the A4.
MAF table took GM a long time of testing to get it correct so I do not suggest the stock MAF be replaced or table mucked with unless it is just a slight tweak in tuning.
There is no way you can test and determine all the correct values to replace in that table, plus have it match injector flow for best performance.
MAF table took GM a long time of testing to get it correct so I do not suggest the stock MAF be replaced or table mucked with unless it is just a slight tweak in tuning.
There is no way you can test and determine all the correct values to replace in that table, plus have it match injector flow for best performance.
Re: LS1Edit issue If you are using a TH400 or some other similar transmission, then naturally, the PCM isn't going to control the line pressure. However, the MAF doesn't just contribute to the line pressure as well.
When messing with fueling, it has always been my opinion that it should be done with the Injector Flow Rate tables. They directly affect fueling without any unexpected side effects.
Good Luck,
Kevin
When messing with fueling, it has always been my opinion that it should be done with the Injector Flow Rate tables. They directly affect fueling without any unexpected side effects.
Good Luck,
Kevin
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TECH Resident
Joined: Jan 2002
Posts: 754
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From: USA
Re: LS1Edit issue [quote
So your saying don't play with the MAF tables at all, just injector pulse widths? Does this also apply to M6's?
[/quote]
The MAF is a Read Only sensor, just like the water temp sensor.
The PCM has to compare the output of MAF frequency with what is in a table, then takes into account what other sensors are reporting, do some math and then make a change.
Whereas in tuning the injector flow that is instead of a read only function is command control that only needs to look at engine load and then command how long an injector will be on.
So injector flow is how the engine controls what the AFR is rather then making up values in the MAF table and hoping those values along with the other sensors end up with a AFR your wanting.
As I mentioned a slight tweak is OK but once you start mucking with that table and if your not using the correct values there is other ill effects from (lying to PCM) this such as delivered torque is now being calculated incorrectly and this effects both A4 and MN6 based cars.
Using injector flow table then is simple and you know the outcome, lower values means go richer, higher values = leaner.
So your saying don't play with the MAF tables at all, just injector pulse widths? Does this also apply to M6's?
[/quote]
The MAF is a Read Only sensor, just like the water temp sensor.
The PCM has to compare the output of MAF frequency with what is in a table, then takes into account what other sensors are reporting, do some math and then make a change.
Whereas in tuning the injector flow that is instead of a read only function is command control that only needs to look at engine load and then command how long an injector will be on.
So injector flow is how the engine controls what the AFR is rather then making up values in the MAF table and hoping those values along with the other sensors end up with a AFR your wanting.
As I mentioned a slight tweak is OK but once you start mucking with that table and if your not using the correct values there is other ill effects from (lying to PCM) this such as delivered torque is now being calculated incorrectly and this effects both A4 and MN6 based cars.
Using injector flow table then is simple and you know the outcome, lower values means go richer, higher values = leaner.
Re: LS1Edit issue unless you are adjusting it just a little bit (no more than 5%), I wouldn't mess with the MAF frequency table. It will also cause unneccessary unlocking of the torque converter when cruising during highway driving.
Thread Starter
On The Tree
Joined: May 2002
Posts: 189
Likes: 2
From: MO
Re: LS1Edit issue Anyway I can find out what that % of mucking up my MAF is? I believe its a high percentage!
I dropped off my A4 today after just having 20,000 miles on the 1999 trans clock, and less than 300 miles after my H/C install with dyno tune. 
Can this be true!
I dropped off my A4 today after just having 20,000 miles on the 1999 trans clock, and less than 300 miles after my H/C install with dyno tune. Can this be true!