Engine Management eCtune , Crome , AFC , FMU , Zdyne , Hondata , EMS , TE , Uberdata Anything to control your fuel, spark needs!

Problem with vafc hack

Old 01-14-2004, 06:52 PM
  #1  
1.0 BAR
Thread Starter
 
Join Date: Dec 2003
Posts: 250
Default Problem with vafc hack

I am running a vortech supercharger @ psi and am having some problems.
I have my settings at -40 from 1000 to 3500 rpm. then i -40 from 4000 to 5000, then i have -39 to 7000, then -38 to redline. Problem is i am throwing codes 13 and 77. Each time i have been leanin it out 1% at whatever rpm i am throwing the code at. but it still throws the same codes. How lean can i go before i start leanin out and hurtin my engine?
slammin86 is offline  
Old 01-14-2004, 06:59 PM
  #2  
1.0 BAR
 
Join Date: Sep 2003
Posts: 453
Default Re:Problem with vafc hack

actually I think leaning it out is probably part of the problem with the code 13. I wouldn't worry about that one - it is pretty common with the hack and doesn't seem to affect performance. I have no idea what a code 77 is tho.
d16tuner is offline  
Old 01-14-2004, 07:16 PM
  #3  
3.0 BAR
 
Join Date: Apr 2003
Posts: 2,260
Default Re:Problem with vafc hack

Originally Posted by slammin86
How lean can i go before i start leanin out and hurtin my engine?
Depends on injector size. There is a formula in the Engine Management FAQ, section 2. I wouldn't go below the settings calculated for you setup using that method. IF you're still throwing baro, then I would try a set of larger injectors (I think you're running 390s, right?). Then you can still scale MAP input back futher, but still have the right amount of fuel.
TurboEF9 is offline  
Old 01-14-2004, 07:39 PM
  #4  
1.0 BAR
Thread Starter
 
Join Date: Dec 2003
Posts: 250
Default Re:Problem with vafc hack

Originally Posted by TurboEF9
Originally Posted by slammin86
How lean can i go before i start leanin out and hurtin my engine?
Depends on injector size. There is a formula in the Engine Management FAQ, section 2. I wouldn't go below the settings calculated for you setup using that method. IF you're still throwing baro, then I would try a set of larger injectors (I think you're running 390s, right?). Then you can still scale MAP input back futher, but still have the right amount of fuel.
im usin 440's....how much more can i scale them back?
slammin86 is offline  
Old 01-14-2004, 07:55 PM
  #5  
3.0 BAR
 
Join Date: Apr 2003
Posts: 2,260
Default Re:Problem with vafc hack

Use the formula in the FAQ. It's very simple. Plug in your injector size, 2 seconds later, you have your base limit. Don't go below that limit.
TurboEF9 is offline  
Old 01-14-2004, 08:16 PM
  #6  
1.0 BAR
Thread Starter
 
Join Date: Dec 2003
Posts: 250
Default Re:Problem with vafc hack

Originally Posted by TurboEF9
Use the formula in the FAQ. It's very simple. Plug in your injector size, 2 seconds later, you have your base limit. Don't go below that limit.
i have already done that.....it says -46+ 5 for injector latency....but it also says to go up 1% per 1000 rpm;s.....according to the formula i am runnin lean now....
slammin86 is offline  
Old 01-14-2004, 08:26 PM
  #7  
3.0 BAR
 
Join Date: Apr 2003
Posts: 2,260
Default Re:Problem with vafc hack

You are running 440cc injectors..

240 / 440 = -0.54
-0.54 - 1 = -0.45
45% is your fuel flow difference.

-45% + 5 = -40%
40% is your corrected fuel flow.

Do not go below -40%!!!

[EDIT]
Keep in mind, -40 cut across the board will run you lean up top due to higher air flow rate. That is why you correct 1% per 1000rpms.
[/EDIT]
TurboEF9 is offline  
Old 01-14-2004, 08:39 PM
  #8  
1.0 BAR
Thread Starter
 
Join Date: Dec 2003
Posts: 250
Default Re:Problem with vafc hack

Originally Posted by TurboEF9
You are running 440cc injectors..

240 / 440 = -0.54
-0.54 - 1 = -0.45
45% is your fuel flow difference.

-45% + 5 = -40%
40% is your corrected fuel flow.

Do not go below -40%!!!

[EDIT]
Keep in mind, -40 cut across the board will run you lean up top due to higher air flow rate. That is why you correct 1% per 1000rpms.
[/EDIT]
I have to dip to 41 for 4000 and 4500 rpm under low throtel....if i go with 40 i throw a cel, code 13. any ideas

slammin86 is offline  
Old 01-14-2004, 08:47 PM
  #9  
3.0 BAR
 
Join Date: Apr 2003
Posts: 2,260
Default Re:Problem with vafc hack

That is dangerously low. By that time, you should be at 8psi (at least). And since you're running at your flow difference, you're effectively relying on your stock (240cc) injecto pulse widths to compensate for the increased cfm.. which it will not.

[EDIT]
..oh, and no, I don't know why you're throwing a code. A -40% cut should be fine. I run -34% at 8000rpm without a code. Maybe Baro needs more massaging than MAP. ..or, it has to do with that 77(I have still yet to find this code listed on ANYTHING.. you're sure it's correct?) code you're throwing.
[/EDIT]
TurboEF9 is offline  
Old 01-14-2004, 09:06 PM
  #10  
1.0 BAR
Thread Starter
 
Join Date: Dec 2003
Posts: 250
Default Re:Problem with vafc hack

Originally Posted by TurboEF9
That is dangerously low. By that time, you should be at 8psi (at least). And since you're running at your flow difference, you're effectively relying on your stock (240cc) injecto pulse widths to compensate for the increased cfm.. which it will not.

[EDIT]
..oh, and no, I don't know why you're throwing a code. A -40% cut should be fine. I run -34% at 8000rpm without a code. Maybe Baro needs more massaging than MAP. ..or, it has to do with that 77(I have still yet to find this code listed on ANYTHING.. you're sure it's correct?) code you're throwing.
[/EDIT]

I think its probably code 67...bad cat...
what are some warning signs that the cat is goin out?
with the vortech supercharger i dont achieve 8 lbs of boost till about 8000 rpm....i rarely see boost below vtec
slammin86 is offline  

Thread Tools
Search this Thread
Quick Reply: Problem with vafc hack


Contact Us - Sitemap - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.