View Full Version : Learning View Screen Shots what can I do to fix the first fuel trims?

01-07-2013, 11:52 PM
So my cars been running a little rich and has been stalling sometimes since I made a few changes and I was just trying to correct them. I still need to get my tune finished up but I was just trying to get driveability spot on since thats all I really use the car for lately. Here is a screen shot of my first learning view..
I increased my injector flow scaling by 5% in this one.
It appears that fixed the 11.20-<20.00 and the 20.00-<80.00 range but how can I fix that 0-<11.20 range? Any help would be awsome!!

Justin 05 Sti
01-08-2013, 08:59 AM
MAF scaling.

The RomRaider logger has a built in tool to help do it.

01-09-2013, 10:11 PM
Yeah im gonna try to attempt to use that tomorrow ill be back by if I have any other questions. Thanks

Justin 05 Sti
01-10-2013, 10:35 AM
For that little of airflow the sampling you'll want to do will be at idle and creeping around a parking lot in gear.

01-15-2013, 01:52 PM
Definitely don't want to be using injector scaling for this as that will make an overall change to the entire fueling of the car, WOT fueling, spool, etc.

Justin is spot on with the MAF scaling, but when you make changes in that table it can make the graph look goofy if you don't know what your doing. Key is to keep the scale/curve smooth as with the maps, as that is how the car will transition thru the tables/cells as you drive.


01-16-2013, 06:25 PM
So do you think I should change the injector scailing back to where it was and just try to scale the maf better?

Justin 05 Sti
01-17-2013, 08:34 AM
That would be the most proper way to do it.

01-18-2013, 06:07 PM
So today I managed to do some driving for about an hour logging with the maf scailing tool in romraider and this is the changes it made how do they look?

01-20-2013, 06:52 PM
Well after loading that on and back to 780cc in fuel injector scailing im at -6.20 in 0-<11.20 -3.00 in 11.20-<20.00 and -4.00 in 20.00-<80.00 after 90 miles. Which isnt to bad I guess but could def be better what do u think keep on logging and adjusting? It just really sucks to drive the first 20 miles or so after a reflash.

Justin 05 Sti
01-20-2013, 07:19 PM
For this type of stuff long logging runs with big data sets are helpful to get it perfect. Within 5% is doing good.

01-21-2013, 02:20 PM
Everything I read says not to do sudden throttle changes but idk exactly how exact you have to be on that.

- - - Updated - - -

Im beginning to wonder if my tial q spring is wrong my issues have been a crazy up and down idle and will sometimes even stall. I was thinkin bad maf acailing but ive got it down closer but its still pretty much the same crappy idle. I have an 11psi spring in it and I see 22.5hg of vacuum. I was thinking of putting a washer in and see if that helps. Id like to be sure its not the spring before I keep trying to scale the maf.

01-21-2013, 10:58 PM
Well not 100% sure yet because I only drove it home but I think that was a giant part of my issue. After work and doing some reading I put a washer in my bov and now everything seems to be working perfect. Maybe down the road ill do it right and just get the 12psi spring but idk. but now that thats good I think maf scailing might go a little better now.

01-22-2013, 12:32 PM
Take the recirc hose off the BOV and look in it while idling and see if the valve is open or opening and closing slightly.


01-22-2013, 08:57 PM
Its a vta and its not opening now pretty sure it was tho because its like night and day with the washer in it. No stalls afrs are looking great and it almost instantly wants to be in boost which I dont let it yet because im sure I need open loop scailing done and nothing has been touched really for wot.