OBD-I to OBD-II swap

[wolfnacht]

I searched for several hours on a Direct OBD-I to OBD-II swap tutorial but found no answer, I have a 95 TI with OBD-I and as there are not Many aftermarket DME/ECU options available I would like to upgrade to OBD-II, for that, and a few other reasons...

I imagine it there wasn't some darastic change between the sensors, PDC, and how they communicate with the DME, if sensors need be changed I can change them, unless they are completely different between the M42 a d M44 engines...
and I'm also aware that I would have to personally wire in the OBD-II panel...
unless an entire Wireharness swap/replacement is required...

I'm sure it wouldn't be as difficult as one would assume but rather tedious...

[Marv17]

i think you would have to switch the motor to a M44 to have a OBD II engine harnese to work. but thats just me...

[pdxmotorhead]

War Chip Instead?NOt perfect but way easier than a OBD upgrade...

Dave

[roadrash]

Are you trying to upgrade just the OBD system & sensors, or do you plan to swap the engine also?

Also, it seems like this would cause a lot of headaches if you have to do emissions testing, or if you ever want to sell the car.

[tiFreak]

Originally Posted by roadrash

Also, it seems like this would cause a lot of headaches if you have to do emissions testing, or if you ever want to sell the car.

I don't think it would matter, there's no computer tests that get done on an OBDI car so as long as the instrument cluster doesn't resemble a Christmas tree you should be fine

[wolfnacht]

War Chip? and I am lookin to just Upgrade from OBD-I to OBD-II but was considering pulling a 2.3 or a 2.5 out of another 3 series of similar year in the future if everything will bolt properly... As far as emissions go... the place I goto just checks the gas cap and MAYBE a sniffer test... aside from that... yeah, I already have half the car apart... had to get Starter rebuilt (burn out and caught fire =S) since I ripped the upper and lower intake out I figured I'd get the Alternator rebuilt (TIfreak-You were right, was only charging at 12.3volts on a good day alternator was going) and replace the 2 knock sensors that are starting to crack as well as a the Vaccum tube going from the Intake Tube to the thingie that spiders out to the injectors and what looks like a little vaccum pump or valve/controller of some sort....

So generally speaking Would would it consist of? Just Harness/DME swap? or About EVERYTING... sensors etc? and any other brittle parts I may need to change while im under the hood ( the tube related to the cooling system was already replaced as well as upper gaskets)

EDIT- I know this is origonally my OBD-I to OBD-II swap question thread... but I figured it be simpler to as ?S here instead of opening a new thread...

[xxxJohnBoyxxx]

I'm not sure why you want to change over to OBD-II. There is not much better between the two. Harder to tune. You can get more codes from a scanner is the better point. EWS is a pain in the butt. There is a lot involved to make it work right but I can steer you in the right direction if your dead set on doing this.

Here is what I need to tell you what you will need to change over if you have to do this in your life-time. Year and model car and motor.

Like a 1995 M42 would be the least expensive & best to change over due to it being right in between the change and having dual purpose mounting for sensors for both OBD systems...

John Smith

[9G3Series]

Well! This is what I’ve been wondering for long as well. Cauze, the late m42 like the ’95 has most sharing parts with m44, i.e., serpentine drive belt, compatible alternator and ignition coil pack for instance. But there are many differences still among them that I could recall for now.

1st, throttle body, they are different in TPS, throttle position sensor, and ICV, idle control valve, so the whole TB need to swap and don’t know can it be bolt on the m42 upper intake body or not.

2nd, MAF and the air temp sensor from the m44, OBD-II, have to come in replacing the m42 AFM, air flow meter. Stock m44 air filter housing or m44 cai kit also need.

3rd, O2 sensors, m44 got 2 of them while m42 has on only 1 and I think they are different. So, 2 O2s from m44 gonna need. I don’t know the old hold can be used or it need to drill 2 more holes for those sensors.

4th, crankshaft sensor, I think this is the most tedious part on the swap since the m42 has front mount by the crank pulley while the m44 is rear mount somewhere by flywheel, I believe. I think, again, the signal should be in contrary; so, it gonna need some genius to work on.

And most of all, it gonna need the whole m44 wiring harness and dme with matched ews key.

Will you change you mind? lol

[xxxJohnBoyxxx]

The crank positons is not a big issue I run the front 1995 sensor on my M44 since I have a M47 crank in my car for the 2.1L stroke. The sensor plug is the same so my ODB-II DME does not care about it. Issue is I had to run 1995 timing chain covers since they have the boss to hold the sensor. You are correct on the rest... Good post

[9G3Series]

Marvelous! John This is it! So, now I got a complete idea on obd2 swap.

But we don’t have that much m44 pieces around here in Bangkok. I’d rather wait for the deal on ebay to come around. Or may be, the whole m44 motor or may be an m52b28 deal form Japanese junk yard, the most used parts resource of Thai bimmers. It depends what’s the deal and most of all the money in my pocket at that moment though. lol

By the way, for anyone who willing to do obd2 swap. You also need an m44 air hose that connecting between the intake boot and fuel injector air charge. If you keep the stock fuel injectors there. It’s a straight hose but on m42 is a 3-way y-shape that the another end go to ICV. I can’t find the part# from realoem, don’t know what page is it though. Sorry

-George

[wolfnacht]

Finally got a computer online and now that i read that... I dont think Im gonna do the obd-II swap EWS sounds like too much of a pain...

Any Good tune up options avail. fer the M42 eg. DME, Injectors, Internals, etc?

[tiFreak]

could always get a Dinan chip, only $200 and it gives decent gains, nothing that will throw you back in the seat but 11 horsepower and 19 ft/lbs of torque isn't bad for the price, only problem is you'll have to find a Dinan dealer because they don't sell them on the website