1997 m3 sedan with s54 swap

[Bry5on]

Also does anyone have a good understanding of how MAP is integrated into the CSL tune? I have tuned speed density with a megasquirt on my old miata. I'm guessing the CSL tune isn't running speed density or using MAP as the main load axis but it's using it to apply a correction factor at longer timescale?

MAP is used to actively correct for fueling only during light throttle within some limitations. karter16 has detailed the function down to the calcs.

[3staxontheradio]

I'm running it off of the brake booster line. Fitting that in the E36 chassis was actually a little challenging, there is less space behind the airbox than on the E46.

I'll check my LTFT next time they are built up but I don't remember seeing huge values in there, I cleared them out today without looking again. This will be a lot easier to diagnose once I get my gauge.s installed and can data log easily.

In the time I have owned this car (just over a year), I have done most of the proactive maintenance for fueling, spark and sensors:

Injectors serviced
new coil packs
Fuel filter was supposed to be recent when I got the car. It's also worse on the low end than up top and a fuel filter doesn't really make sense for hwat im seeing
crank angle sensor

I haven't replaced the o2 sensors yet. I have one of them on hand and need to order the other one.

I haven't had a car on an alpha-N or TPS based tune before. MAF tunes obviously gets thrown off badly with vacuum leaks, speed density doesn't really care that much. I would guess that alpha-n Is pretty sensitive to vacuum leaks throwing off fueling at the bottom end of the rev range like a MAF tune?

[heinzboehmer]

Also does anyone have a good understanding of how MAP is integrated into the CSL tune? I have tuned speed density with a megasquirt on my old miata. I'm guessing the CSL tune isn't running speed density or using MAP as the main load axis but it's using it to apply a correction factor at longer timescale?

https://github.com/karter16/CSL_0401_Binary_Disassembly_Notes/wiki/How-the-CSL-MAP-sensor-works

[karter16]

Key in position 2 I get 4.02 volts

Hey just confirming that you definitely have the MAP sensor gain and offset parameters set correctly for whatever MAP sensor you're using? I'm presuming you've already checked that, but thought I'd mention it.

If you're completely confident that that is correct then I'd really start to suspect something in the wiring. I encountered an issue with my first wiring loom (which I was never able to measure or identify) that caused very short duration interruptions in signal. These interruptions weren't visible at 5HZ via TestO and only became apparent when logging at 100Hz with Gauge.S. I know you're very confident with your wiring, but I was too with mine and it proved to be the issue - just thought I'd mention that.

[3staxontheradio]

I'm confident in my splices but I'm also splicing off of a whole bundle of already extended MAF wires from the previous owners adapting the e46 harness to the e36 and I can't see what's under the shrink tubing. It's only 3 wires and I have like 15 different colors of tefzel so probably worth just running 3 new wires and not sharing a ground with the IAT.

Also on map sensor scaling: I have the Bosch sensor and martyns tool shows it on the default CSL map scaling. I assume that's correct?

[3staxontheradio]

I just found out that the crankcase drain hose was disconnected again (the small one under the airbox). I think the fitting is worn out and its popping out of place. Not sure that really constitutes a vacuum leak anymore since its before the throttle bodies so TPS based airflow calc doesn't care and MAP won't care either.

[karter16]

I'm confident in my splices but I'm also splicing off of a whole bundle of already extended MAF wires from the previous owners adapting the e46 harness to the e36 and I can't see what's under the shrink tubing. It's only 3 wires and I have like 15 different colors of tefzel so probably worth just running 3 new wires and not sharing a ground with the IAT.

Also on map sensor scaling: I have the Bosch sensor and martyns tool shows it on the default CSL map scaling. I assume that's correct?

Sharing ground with the IAT shouldn't be a problem - it's the exact same setup I'm running. I believe when I checked the IAT, MAF and MAP are all driven from the same UB (supply) circuit anyway, so ground should be directly the same between them anyhow. But yeah probably worth trying a second set of wiring anyway.

Yep cool if you have the Bosch '101' sensor then the scaling is the default.

[3staxontheradio]

karter16 any chance you could load up testo and see what your key position 2 MAP voltage reading is when the car isn't running?

[karter16]

karter16 any chance you could load up testo and see what your key position 2 MAP voltage reading is when the car isn't running?

Even better, found a photo from a few months ago.

[Slideways]

I just found out that the crankcase drain hose was disconnected again (the small one under the airbox). I think the fitting is worn out and its popping out of place. Not sure that really constitutes a vacuum leak anymore since its before the throttle bodies so TPS based airflow calc doesn't care and MAP won't care either.

Someone said that BMW might have updated that hose at some point to make it a tighter fit in the airbox. A hose from a later S54 or a new one from BMW should fix the issue.

[heinzboehmer]

Someone said that BMW might have updated that hose at some point to make it a tighter fit in the airbox. A hose from a later S54 or a new one from BMW should fix the issue.

New line worked on my car for a bit, but eventually started falling out again. Think it was just the newer o ring holding it in better.

Ended up modifying the boss on the airbox. Hasn't fallen out since: https://nam3forum.com/forums/forum/m...403#post328403

[3staxontheradio]

heinzboehmer You had a noticable improvement in ltft and drivability with that line being installed. I did a school dropoff run this morning and the car felt great again. Both resetting adaptions and I guess that drain hose?

I don't really understand why this constitues a vacuum leak when you aren't running a maf. The airbox before the throttle bodies isn't a vacuum source and it's before the air is "metered" by throttle position or MAP. The oil pan is getting essentially atmospheric pressure from the airbox too so 🤷

[Bry5on]

That shouldn’t constitute a vacuum leak on the s54 - it’s got to be something else. ICV maybe?

[samthejam]

I have had the karbonius box on the car for about a week- the sound is great but I'm having some issues I think are related to my map sensor install. I also updated the bootloader with MpowerE36's tool and am currently running Bry5on mullet tune. The car is down on power, especially on the low end, and throttle response is lazy. When I first did the airbox install everything felt great except for some hiccups with the HTE tune that happened to be on the DME before I got it- not faulting the tune, its not for my car and I know nothing about it other than it says its an HTE tune for someones CSL car.The lazy low end power and throttle response happens with both tunes and if I reset adaptations it gets better temporarily. Long term trims are picking up bad data and throwing the car fueling off. Also with both tunes I get some on throttle hiccups and hesitation at medium to high loads and 4000ish RPM. I think this is just a fueling issue in line with whatever is throwing long term trims off.

I wired my MAP sensor by splitting the IAT ground off of the MAF harness (its all properly crimped open barrel splices, not worried about wiring and crimp quality). Martyn has a very helpful MAP sensor testing guide here:

https://www.ecuworx.co.uk/2016/03/15/checking-your-map-sensor-is-working-when-running-a-csl-clone/

I'm getting slightly different voltages when the car is off and when the car is idling, I think my ground location is causing a signal offset and I'm curious if other people have also grounded both MAP and IAT off of the same wire, its pin 25 on X60003.

Key in position 2 I get 4.02 volts and idling at about 900rpm I get close to 1.3v for and a 360 mbar reading. I live at about 400 feet of elevation so that doesn't really account for the difference in voltage when the car is off at position 2. Atmospheric pressure where I am should be 998.6 mbar which is a much smaller voltage difference.

Also very curious to hear what other people with correctly running CSL cars are getting when they run the testo tool linked from martyns article. FWIW the tool is x86 not x64 and it took me a minute to figure out why I was still getting MSVCP100.dll errors when I have Visual Studio C++ redistributable packages installed (I only had x64 version).

What did you do for the clutch switch DME settings? jayjaya29 we did yours like the Z3M right? Asking because that can create throttle lag like issues and stalling issues if it has GPS and clutch switch logic, unlike Z3m only looking for the clutch switch

[3staxontheradio]

About to drive to Atlanta to pick up a 500mm bed 3d printer to use for fdm header test parts but I took a quick look at ltft. They don't look far off (yet?) There have about 45 minutes of city and highway driving on them. I'm going to keep watching to see if they drift.



Also my clutch switch was set to switch+gps so I guess I need to change that.

I also need to code out the dsc stuff and figure out why my brake switch is complaining. Brake lights come on just fine and the error count for that when I have been tracking it is huge.