survey: Who is runnig a 24v swap with obd2?

[AndrewK]

Update. My OBD2 S52 swap into my '89 four door is up and running as of last weekend. Surprisingly it started on the first try. I drove it for the first time on Friday. Awesome! I'm smitten and my E30 M3 is already jealous. :D

Unfortunately I had a really bad trans fluid leak. So bad in fact that by the end of my test drive the transmission was dry. Bimmerworld had their open house Saturday and I really wanted to get the car there to show it off. So, one of my friends helped me swap in a spare trans on Friday night. We finished around 3:30am. Made it to the open house tired and exhausted, but with a major feeling of accomplishment. On top of that the BW guys liked the swap so much I won the Show-n-Shine award for "Most Unique"! Makes the last two months of hard work worth it.

I'm still not completely done however. I couldn't fit the front sway due to a conflict with the downpipe. Custom exhaust is in the works. I'm temporarily running an old E36 exhaust that I literally pulled out of the trash. I need to have my custom ECU done so I can extinguish the CEL. Oil level sensor isn't working even though I'm certain I wired it correctly. A few other issues, but all in all so far I'm convinced I made a wise decision to remain OBD2.

[Mr.SWISS]

Update. My OBD2 S52 swap into my '89 four door is up and running as of last weekend. Surprisingly it started on the first try. I drove it for the first time on Friday. Awesome! I'm smitten and my E30 M3 is already jealous. :D

Unfortunately I had a really bad trans fluid leak. So bad in fact that by the end of my test drive the transmission was dry. Bimmerworld had their open house Saturday and I really wanted to get the car there to show it off. So, one of my friends helped me swap in a spare trans on Friday night. We finished around 3:30am. Made it to the open house tired and exhausted, but with a major feeling of accomplishment. On top of that the BW guys liked the swap so much I won the Show-n-Shine award for "Most Unique"! Makes the last two months of hard work worth it.

I'm still not completely done however. I couldn't fit the front sway due to a conflict with the downpipe. Custom exhaust is in the works. I'm temporarily running an old E36 exhaust that I literally pulled out of the trash. I need to have my custom ECU done so I can extinguish the CEL. Oil level sensor isn't working even though I'm certain I wired it correctly. A few other issues, but all in all so far I'm convinced I made a wise decision to remain OBD2.

SWEET! Try switching your sensor wire and your hot wire on the oil level sender, I am almost positive the center is the ground.

[Len013091]

FWIW, I saw someone mention that the E46 is a returnless system, this is only partially correct. The fuel rail only has one line to it, but the filter/fpr has a supply and return. The pressure is regulated before it even gets to the rail. I've been looking in to running the e46 rail and filter on my M50 swap due to the simplicity of the set up, and the test port on the rail. (I also have an e46 which I steal ideas from lol)

[pandaboo911]

Leave it obd2 but go with the m50 mani

Also the center pin on oil level sender must be grounded, the sides are for oil levels low and sufficient.

[AndrewK]

Leave it obd2 but go with the m50 mani

Yes, definitely M50 manifold! Open up the intake and let the engine breathe. I'm running one, removed the traction control throttle body, and simply stuck a cone filter on the MAF. Even though the ECU hasn't been tuned yet, it positively rips up to the rev limiter. By contrast I've driven stock S52s and they don't rip to redline so much as wheeze their way there. Not how a NA M engine should be. I've tracked an S14 for many years and my first hot lap driving an stock S52 powered car was so disappointing to me. For me, the high RPM performance was of utmost importance to improve on my swap. The M50 manifold helps drastically in this regard.

Also the center pin on oil level sender must be grounded, the sides are for oil levels low and sufficient.

As mentioned I'm fairly certain my wiring is correct. I studied the ETMs thoroughly and it looks to me like you wire the E34 sender in exactly the same order as the E30 sender. Pin 1 is low level. The center (pin 2) is ground. Pin 3 is full/sufficient level. I will swap 1 and 3 wires just to double check. If that doesn't fix it I suspect the sensor is bad.

[Wanganstyle]

FWIW, I saw someone mention that the E46 is a returnless system, this is only partially correct. The fuel rail only has one line to it, but the filter/fpr has a supply and return. The pressure is regulated before it even gets to the rail. I've been looking in to running the e46 rail and filter on my M50 swap due to the simplicity of the set up, and the test port on the rail. (I also have an e46 which I steal ideas from lol)

its got to return somewhere, no return from engine is the definition.

if the fpr/filter was in tank, then it would truely be a "returnless system" but really annoying to service!!

you can use the 5.0 bar fuel pressure regulator if you want to upgrade to e36M/e46m pump and high pressure clamp fittings for it if really desired; some OEM systems use this.

[Wanganstyle]

What have you removed from your OBD-II swap that has enabled you to pass smog in CA? I'm going OBD-II and smog is on the back of my mind

my instance was not a swap;

2 cars "passed" the dyno+ plug in obd2 port to brain machine as thus:

1. 97 5mt M3. Stock ECU, 3.38 final drive, AA air box.

2. 98 m3 auto with smog pump deleted, stock air box, stock ecu. 3.38 stock final drive.

failed instance:

3. 98 m3 auto smog pump deleted, stock air box + 4.10 final drive = fail on NOx part of emissions only, if the smog pump was installed the final drive change would have been ok imo.

removed:

obd2 air pump, blocked it.
disabled/capped a few solinoids/ports on the intake manifold for the egr switching and switching to M50 intake manifold

as long as the cats are good it seems to pass, the air pump CEL will return eventually.

[jrez]

obd2.

Did it back in 2005.

[AndrewK]

I finally got a code reader and here are the results. Nothing surprising or unexpected. Maybe this will help future OBD2 swappers understand what needs to be removed/flashed from the OBD2 ECU in order to extinguish the check engine light. Of course this is in addition to EWS removal and a good tune if you see fit. Note, my S52 is originally from a '97 M3. Other OBD2 engines/ECUs may give you different codes.

3D – After cat O2 sensor heater, Cyl #4-6
(I'm not running the post-cat O2 sensors.)

4F – After cat O2 sensor heater, Cyl #1-3
(ditto)

32 – EVAP system running losses valve
(This is because I'm using an OBD1 style fuel rail with fuel pressure regulator located on the rail and not the OBD2 style with FPR located under the car. Mentioned in this and other OBD2 swap threads.)

3E – Secondary air system, switching valve
(I removed the air pump valve mounted under the intake manifold between cyl 1 & 2 runners. If removed, and you keep the OBD2 intake manifold, cap the vacuum line to this or you will end up with an vacuum leak here.)

23 – Secondary air system relay/pump
(Obvious. No more air pump or relay.)

0B – EVAP system pressure sensor
(Either this is the E36 fuel tank pressure sensor, E36 fuel tank evap crap in the spare tire well, or both. Obviously an E30 is not equipped with any of this.)

[matt]

I can turn all that stuff off. (For off-road use only.)

[Mr.SWISS]

I finally got a code reader and here are the results. Nothing surprising or unexpected. Maybe this will help future OBD2 swappers understand what needs to be removed/flashed from the OBD2 ECU in order to extinguish the check engine light. Of course this is in addition to EWS removal and a good tune if you see fit. Note, my S52 is originally from a '97 M3. Other OBD2 engines/ECUs may give you different codes.

3D – After cat O2 sensor heater, Cyl #4-6
(I'm not running the post-cat O2 sensors.)

4F – After cat O2 sensor heater, Cyl #1-3
(ditto)

32 – EVAP system running losses valve
(This is because I'm using an OBD1 style fuel rail with fuel pressure regulator located on the rail and not the OBD2 style with FPR located under the car. Mentioned in this and other OBD2 swap threads.)

3E – Secondary air system, switching valve
(I removed the air pump valve mounted under the intake manifold between cyl 1 & 2 runners. If removed, and you keep the OBD2 intake manifold, cap the vacuum line to this or you will end up with an vacuum leak here.)

23 – Secondary air system relay/pump
(Obvious. No more air pump or relay.)

0B – EVAP system pressure sensor
(Either this is the E36 fuel tank pressure sensor, E36 fuel tank evap crap in the spare tire well, or both. Obviously an E30 is not equipped with any of this.)

Mine has the same codes along with a mechanical vanos stuck code.

Did that yesterday afternoon and went out cruising and I had/have a flat spot in my power band around 5K it just falls off. Going to unplug them reset ECU and check it out.


Brett @ Technica said I needed to have the purge valve and SAS switching valve and that the actual systems cannot be turned off and I NEED to run the OBD2 FPR.......or deal with the CEL :dot: