BMW-Bob

Thank you for the clarifications and explanations. I have some work to do before I can work on the hot restarts.

This brings up a question I've been fighting to figure out. I have G4X+ for BMW M50, adapted to M42 4 cylinder. I have the engine tuned and we did ~15 hours of endurance racing this weekend. Car ran great... BUT.... I've been trying to get HOT restarts tire fire on the first crank. It takes multiple tries on HOT restarts. Sometimes it fires, sometimes it does not. Really stressful during an endurance race after a refueling pitstop. - I have KEY ON Prime set to ON, but do not have prime pulse time populated in the table. If I populate, failed starts tend to flood the engine and starting is even more difficult. I use the KEY ON set to ON so the fuel pump will always pressurize the system. Questions - For the mentioned 5sec startup timer, - can this be adjusted? - what is the correct starting procedure? 1.) Key-On and Instantly go to crank?, or 2.) Key-On wait ~1 sec for the ECU to initiate, then crank as soon as you see the Tach Sweep Start? - for all the enrichment table settings (Crank, Post Crank, Post Start, etc) these are percentage % increase over what number? - Starting (cranking) at full operating temp, little to no enrichment needed, what is the ECU using for a reference fuel number? - It is the 0 to ~500 RPM range in the fuel table?

All, Thank you for the reply. I did get CLL Auto to work. I was pressed to time to get to the endurance race over the weekend. I had to populate and play with the Lambda Gain table {I think that's what it was called = having a rough monday morning after a race weekend} Engine ran great. Huge improvement in power and fuel consumption ! I did notice that I now have an ignition misfire in the 5300-5800 rpm range at full load / WOT. This didn't happen on the chassis dyno. Checking plug wires and plug heat range?

Hello everyone, quick question about CLL modes. My tune is really close with the CLL off, full range from part throttle cruise to full range rpm WOT. I am using a Bosch LSU ADV Wide Band sensor and controller. 14.7 idle to ~13.1 WOT (big cams - 4 cylinder) With CLL WB Stoich mode turned on, CLL works and I can see the idle AFR correcting and oscillating around 14.7. Adjusting the gain setting helps the response time, undershoot and overshoot. I can get this to work. With CLL WB Auto mode turned on, I'm watching the idle AFR in the ~15's and increasing, the CLL status shows reducing fuel. It cannot seems to correct the AFR to the target 14.7 It seems to be correcting in the wrong direction, and keeps leaning out the mixture. CLL WB Auto does not seem to work. I'd like to use CLL Auto to have full range correction. WB Stoich only seems to correct for part throttle, low load cruise to hold 14.7 I don't have a file handy to attach, I'm at work and cannot access it right now. suggestions?

General question about Prime & Crank Enrichment, I have the engine running, but if I make various setting changes while engine OFF and connected to the ECU, it does not start on the first try. Yes, I upload to ECU and save the file. If I key off, and retry, immediately Going to ON, then CRANK, the engine will fire right up. It is almost like there is a timer that expires during Key ON while I am making adjustments. Timer expires, and on Prime or Crank Enrichment. Key OFF, seems to reset the timers to 0

Hello Adamw, thank you for the reply. -114° is where I have the offset. Sorry typo, I forgot the '-' negative sign. I did find the problem last night. When I was testing the ignition, I found the #2, 3, and 4 were not wired correctly. Lesson learned, do not trust factory manuals! BMW M50 have direct fire coil on plug. Pre-1994 BMW M42 used the same coils, but the coils were remote mounted and had plug wires. 1994+ M42 changed to a 4in1 integrate coil pack, part number 12131247281, and used plug wires. These are all 'dumb' coils. I grafted the M42 4in1 coil harness into the M50 engine harness. That's were I made the mistake. I corrected the wiring mistake. Now the ignition tests show the correct plugs firing. Engine still coughed and missed. I changed the ignition offset from -114° to 246° and it fired right up! Had to do some BIG changes in the master fuel. It was VERY rich. I'm running bigger injectors. Need to do some work on the idle control and it won't rev past ~2500 it goes lean... but it is running and I can start tuning. I'm excited and eager to learn and tune with LINK. Hoping for big gains, more control, and a better running engine!

Hello All, I am new to Link ECUs. I've tuned several BMW factory ECUs before switching to Link. I have the Link G4X BMW, connected to a factory M50 harness (6 cylinder), but running the harness and a M42 (4 cylinder). I have 2 less injectors, and 2 less ignition coils. I am using the base map for the 6 cylinder with changes for 4 cylinder firing order. I have the all of the calibrations done, and the triggers calibrated. I cannot get this to start. It will cough and misfire, but not enough power to run on it's own. 1 of the areas I think I might need to go back and check is the trigger calibration. I have the offset set to 114° and verified it with a timing light. The M42 cam trigger is different from the M50. I know from setting the cam timing, the cam trigger pin will pass the sensor at ~30° after TDC2 with the firing order of 1-3-4-2, thus after the trigger 2 is seen, the firing order starts at the beginning TDC1. I've tried 360° offset also with little change. Same cough and misfire. Planning on checking the ignition wires and coils, and I will look at the trigger scope and other inputs tonight to verify everything. Looking for you replies. I will have the file and logs coming. thanks bobk