Pretty sure this is my first post here on NefMoto so I'd like to start out by thanking Tony and others for all their contributions to this site.  Self tuning has been a long time goal of mine and I feel it's achievable because of the info here.  In December I pulled my 2.7T motor, swapped in a used one and added used K04s, new clutch, FW, O2 sensors and replaced a bunch of seals/gaskets, etc.  I've been reading a lot over the past month while I broke in the clutch and I'm all setup to tune.  I re-flashed my t-box with the stock m-box code and started playing around.  First I coded out my rear O2s and EGTs (one is bad) and monitored/tweaked my LTFTs on stock injectors for practice.

When I bought the used K04s they came with Siemens 630cc injectors and an 85mm MAF.  Today I installed the injectors as the first step.  I drove around for about 30 minutes with different types of load and a few WOT pulls.  Readings from block 32 were 2.4%, -6.3%, 2.8%, -7.0%.  This is with the values from Tony's base m-box with injector adjustment to KRKTE and TVUB. 

I know tweaks need to be made to lower the LTFTs but my main concern is I was getting a lot of misfires (25-75) at idle on one cylinder (plugs are new).  The rest of the cylinders were zero.  If I brought the RPMs up a bit the misfires subsided.  It looks like these injectors were flow tested at one point as four of them have 620 etched into  the body, another has 629 and the one with all of the misfires has 610.  So...

• I know these injectors have a reputation for being inconsistent.  Is what I'm experiencing par for the course with these?
• Should I look at replacing the 610cc injector on cylinder 4?
• Should I just raise the idle RPM and move on?
• Is it expected these misfires will go away as I continue adjusting KRKTE and TVUB?

I just don't want to move forward with tuning until I know I can trust the hardware.

Thanks,

-Roman

i have some very old 630s and I run stock tvub...

i hear the "older" ones are better, ymmv.

OH also i still get occasional misfires at idle. can't get rid of them.

Two problem cylinders (but only those two), and yes, idle speed is stock.

Here are the latencies I used with zero idle misfires:



YMMV of course.  KRKTE @ 0.04673

Thanks, Jason.  I went back to stock last night after it looked like I was running super rich.  I still need to check the LTFTs now that I've put some miles on it.  I am getting throttle cut with the stock values and I wasn't seeing that before.  I'll see how your numbers compare and continue adjusting. 

Really wish my cable supported Tony's licensing.  The full flash can feel like an eternity when you are in a rush.  Might be time to get a supported cable.

NLLM, KFMRES and KFMRESK are stock m-box values.  Aside from coding out the O2s, EGTs and enabling left foot braking I've only touched KRKTE and TVUB.

Page 52 from Greg Banish's book: Designing and Tuning High Performance Fuel Injected Systems states that;

 "At idle it is helpful to maintain a torque reserve to ensure that the engine can quickly respond to changes in resistance. By intentionally operating the engine with less than MBT timing, the ECU knows that it could increase the engines torque almost instantaneously by adjusting back toward MBT. The ECU can also instantantaneously retard timing to reduce engine torque in cases where less is needed for a brief period.. The gap between delivered ignition timing and actual MBT at idle represents the torque reserve that is held for unforseen changes in engine loading later on"