M50B25tu with 21.5lbs injectors (pink tops)

[e34WagonZilla]

Hi.

Recently I've installed some remanfactured pink top injectors (21.5lbs/hr) in my M50, in my e34. I'll describe the issue I'm facing below after a few details on my tune that I've done myself. The injectors were flow test by Race German and verified as functional.

So, before I was running off of the BMWLink x36 M50 base tune with my MAP sensor and TPS calibrated, I had already been running this map for months with some fine tuning to aid idle and fuel economy, nothing crazy as the motor is stock with a full custom exhaust built for the motor I'm swapping in eventually. So last Friday I exchanged the stock green top injectors for pink tops (the purpose is to have more overhead for an e85 tune otherwise I wouldn't be swapping). I also recently installed a wideband sensor in anticipation of this swap and for things moving forward... Enough of the preamble.

So I had modify the entire fuel map to suit the new injectors, input a value of -40% to "Master Fuel Trim" under "Fuel Main" settings, and of course I set the dead times (Voltage x ms) for the pink top injectors, I used information found on a different forum. Some other things I changed to help the car run were "post-start enrichment" due to extreme rich idle in warm-up.

 

So here's my issue.

I've been having a very serious problem where 0-20% TPS input is often lean after coming in off throttle, like it shows up as a 20:1 AFR+ spike in my logs.. but this morning on my commute to work the engine was breaking up very badly and AFR across the board was extremely lean. Audibly misfiring under any load, sounded like a rev limiter.

luckily I didn't have to drive too far like this. I checked my harness and fuel rail to see if there was any issues, none to report. I've been meaning to check my spark plugs and coil packs but I don't think its a problem either. Mainly think there's an issue with my tune but also, this misfiring/breakup issues are completely new since this morning.

 

So I've included my most current tune and my log from this morning, which was 90% of my drive. My knock protection is set up.

 

TIA,

Jesse

M50B25TU - 7000rpm - lean cruise - 24lbs bosch - full exhaust .pclx misfire.llgx

[e34WagonZilla]

https://drive.google.com/drive/folders/1caeh5D-18XS9PFjlvelzVMCgZSekaz4y?usp=sharing

 

I updated some settings regarding closed lambda loop, also recorded another log since then. They are located in this google drive folder I created. Right now working on verifying that my ignition and fuel system aren't an issue.

[Adamw]

You have no accel enrichment working or async fuel, so you will have some issues with transients without these but I think you have something else going on too.  The reported lambda doesnt seem to follow the trend that injector PW shows - ie when PW increases you would expect lambda to get richer.  Obviously with a misfire the lambda sensor isnt useful so we cant put too much weight on lambda alone.   But the lambda doesnt look like it is showing the truth to me.  ie it is idling with the lambda pinned at 1.23lambda which is the leanest the x-series can read, there are not many engines that would be able to idle that lean.  Assuming it is not misfiring at idle then I would suspect maybe the lambda probe is dying or there is an air leak or something. 

I suggest the changes in orange and red below, as a better starting point fr transients, but there is some other non-tune issue by the looks so this isnt going to solve the issue.