The Official OBD1 vs OBD2 argument thread.

[nando]

there's no pin 14 but there's still a VSS signal on the X6031.

[328ijunkie]

Pin 20 on the C101 is EITHER a ground or a needed Hot wire. If you mix it up youll burn the car to the ground as nothing there is fused.
Ive never seen a OBD2 harness with a pin 14.

Pin 14 on the C101 is typically VSS.

[MC Hammered]

If a car is already running a s52 OBD1 setup is there any reason or benefit to change it to OBD2?

[mammoth_e30]

Been doing some homework on this so I know more about what is going on in the OBD2 harness.

The wiring for the swap all seems to be the same (with regards to OBDI) EXCEPT for Pin 14 on the X20 (RPM to cluster). On my OBDII wiring harness Pin 14 is blank. I posed this question to nando and it seems that Pin 1 on the X6031 (one of the two adjacent connectors to the X20) is actually the RPM to the cluster. So is this the ONLY difference with the wiring? I'm pretty sure that it is, but if there is anyone with first hand experience, I'd love to hear from you.

Pin 14 is missing on my OBD2 harness as well aka not used at all w/ OBD2.

Wiring is a good bit different. And the RPM signal is still on the X20. The CEL is however on the X6031.

Edit: CEL is Pin 1 x6031

I am pretty sure with these last two, which I had wrong as well, I have got most of the pins for OBD2 down. I certainly hope so, I've spent enough hours looking at ETMs.

[328ijunkie]

What if I'm trying to go from m50 to s52?

can i stay ODB1 with all the old wiring... or
do I need to buy new wiring harnesses and all that crap?

You can convert your S52 to OBD1. I wouldnt though ;)

I believe you're going to need the OBDII harness because the knock sensors are different, as is the location of the crank position sensor (I think?). However, on a similar note to Pl3wA's question:

I'm doing exactly as the original post outlines; OBDII S52 swap with rear O2 delete, EWS delete, secondary air pump delete, M50 manifold with fuel rail and throttle body, M50manifold.com kit to keep the oil separator drain back to the dipstick tube.

The wiring for the swap all seems to be the same (with regards to OBDI) EXCEPT for Pin 14 on the X20 (RPM to cluster). On my OBDII wiring harness Pin 14 is blank. I posed this question to nando and it seems that Pin 1 on the X6031 (one of the two adjacent connectors to the X20) is actually the RPM to the cluster. So is this the ONLY difference with the wiring? I'm pretty sure that it is, but if there is anyone with first hand experience, I'd love to hear from you.

Wiring is a good bit different. And the RPM signal is still on the X20. The CEL is however on the X6031.

[Gooch]

I believe you're going to need the OBDII harness because the knock sensors are different, as is the location of the crank position sensor (I think?). However, on a similar note to Pl3wA's question:

I'm doing exactly as the original post outlines; OBDII S52 swap with rear O2 delete, EWS delete, secondary air pump delete, M50 manifold with fuel rail and throttle body, M50manifold.com kit to keep the oil separator drain back to the dipstick tube.

The wiring for the swap all seems to be the same (with regards to OBDI) EXCEPT for Pin 14 on the X20 (VSS to cluster). On my OBDII wiring harness Pin 14 is blank. I posed this question to nando and it seems that Pin 3 on the X6031 (one of the two adjacent connectors to the X20) is actually the VSS to the cluster. So is this the ONLY difference with the wiring? I'm pretty sure that it is, but if there is anyone with first hand experience, I'd love to hear from you.

[Pl3wA]

What if I'm trying to go from m50 to s52?

can i stay ODB1 with all the old wiring... or
do I need to buy new wiring harnesses and all that crap?

[328ijunkie]

Obd2 ftw

[jrdeamicis]

I converted my S50 to run OBD2 because OBD1 has it place for old german cars, but not in my new roadster.

Carb legal OBD2 swaps are easy.

Say the engine is from a Z3. AND use a Z3 brain flashed with an S52 tune. Only 2 O2 sensors. All the same other BS.

Everything else is a couple hose clamps, tek screws, and some brain. Remember guys, you gotta use your brain! Keep notes! And don't be afraid to go back to basics in understanding what you are changing.

[325e10]

E34 525i vertical airbox from the m50 cars fits nicely. Sounds like CARB sorta sucks for you cali guys.

[mammoth_e30]

Dont use any cone filter. use the OEM e36 air box or e34 airbox that matches a s52 / m50 engine.

relocation of ABS would be the clean way to do this install.

Cone air filter is not really an OEM part, does not have a C.A.R.B. EO number or sticker. I suppose if you bought a Dinan CARB Legal s52 intake and fitted it to the E30 without causing any emissions it could bar ok with the CARB EO number


*** Yes, I would use the entire S52 rail + its remote under car mounted Fuel pressure regulator and running losses valve, its newer and modern and good. e30 fuel filter is in the back, just plumb it to the oem S52 setup of the e36m. it has a valve and a return to tank from its fuel pressure regulator block.

Thanks for the tips! Done threadjacking.

[Wanganstyle]

I

Do I need to run the e36 FPR?

also what cone filter have people used to pass OBDII BAR?

Dont use any cone filter. use the OEM e36 air box or e34 airbox that matches a s52 / m50 engine.

relocation of ABS would be the clean way to do this install.

Cone air filter is not really an OEM part, does not have a C.A.R.B. EO number or sticker. I suppose if you bought a Dinan CARB Legal s52 intake and fitted it to the E30 without causing any emissions it could bar ok with the CARB EO number


*** Yes, I would use the entire S52 rail + its remote under car mounted Fuel pressure regulator and running losses valve, its newer and modern and good. e30 fuel filter is in the back, just plumb it to the oem S52 setup of the e36m. it has a valve and a return to tank from its fuel pressure regulator block.

[mammoth_e30]

That first Real OEM pic you posted is of the trunk evap tank Wangan mentioned. The 2nd realoem part your E30 already basically has a similar verson in the same place it is on an E36.

Thanks Dave, i picked up that first pictured charcoal filter and an OBDII harness today :)

[328ijunkie]

I am going to be "attempting" a S52 OBDII swap and get it CA BAR passed. I am undecided if I am just going to mock up the air pump and have it deleted from the ECU or if I want to run it. Right now I am only missing the emissions control pump but people are asking $75 or more for it used.

I will have the O2 sensors installed and have looked up CA leagal cats that I will have installed aftermarket with a new dual 2" exhaust. How long do I have till I need to get the car BAR passed once I complete the swap? I just got it smogged this summer.

One thing I did not know about till now is the tank leakage module which I need to look into.



I am interested in seeing this setup on an e30 if anyone has a picture available for reference or even on an e36. My experience is limited with this and I don't have a full M3 to pull parts from or a local car to reference. Do I need to run the e36 FPR?

http://www.realoem.com/bmw/showparts.do?model=BG93&mospid=47488&btnr=16_0202&hg=16&fg=10

is this part #10?

http://www.realoem.com/bmw/showparts.do?model=BG93&mospid=47488&btnr=16_0214&hg=16&fg=10

Thanks!

That first Real OEM pic you posted is of the trunk evap tank Wangan mentioned. The 2nd realoem part your E30 already basically has a similar verson in the same place it is on an E36.

[mammoth_e30]

I am going to be "attempting" a S52 OBDII swap and get it CA BAR passed. I am undecided if I am just going to mock up the air pump and have it deleted from the ECU or if I want to run it. Right now I am only missing the emissions control pump but people are asking $75 or more for it used.

I will have the O2 sensors installed and have looked up CA leagal cats that I will have installed aftermarket with a new dual 2" exhaust. How long do I have till I need to get the car BAR passed once I complete the swap? I just got it smogged this summer.

One thing I did not know about till now is the tank leakage module which I need to look into.

Running losses valve is attached to the fuel filter and fuel pressure regulator under the e36M. run it. a fully pressurized rail system is more efficient and better for your engine than the OBD1 style FPR at end of rail. Why bother even separating the fuel rail and lines??

I am interested in seeing this setup on an e30 if anyone has a picture available for reference or even on an e36. My experience is limited with this and I don't have a full M3 to pull parts from or a local car to reference. Do I need to run the e36 FPR?

http://www.realoem.com/bmw/showparts.do?model=BG93&mospid=47488&btnr=16_0202&hg=16&fg=10

rear spare tire well mounted tank sensor is easily bought and installed. Done.

is this part #10?

http://www.realoem.com/bmw/showparts.do?model=BG93&mospid=47488&btnr=16_0214&hg=16&fg=10

edit: also what cone filter have people used to pass OBDII BAR?

Thanks!